Can Solar Energy Reduce High Electricity Costs in California's Central Valley?

[Ivan Seeking]

This is the paper about the Banki Turbine.
http://agungchynta.files.wordpress.com/2007/03/crossflow-turbine.pdf

Fun stuff! I have considered buying a piece of property just for the hydro potential...

 

[Ms Music]

Which company in http://www.getsolar.com/washington-solar-power-panel-installation-professionals.php" did you get the study from, I'm curious?

This one: http://www.sunergysystems.com/residential-solar/washington-state-solar-incentives" Not sure why they aren't on your list.

I never did get the study done, King County won't let me cut down the trees until I have a building permit. I communicated with the company for a few years, but they gave me a refund since they couldn't do the study.

 

[mbrmbrg]

My professor (who has a PV lab in GA Tech and is the CTO of a PV company) recommends https://www.nrel.gov/analysis/sam/ for playing with the price/kWh for PV arrays.

 

[mheslep]

My professor (who has a PV lab in GA Tech and is the CTO of a PV company) recommends https://www.nrel.gov/analysis/sam/ for playing with the price/kWh for PV arrays.

Thanks, I'd seen a link at NREL before but didn't know if the SW was worth the time.

 

[Bararontok]

Considering the fact that solar panels have a cost efficacy of $7.5/Watt, the purchaser should try to reduce the power consumption of their house so that they do not need to buy too many solar panels and can settle for a handful of low wattage units.

The following article posted below shows the techniques used to reduce energy consumption. With these techniques, the author of this article has reduced their energy consumption from an average of 1,200kWh/month to 480kWh/month, which is a 60% reduction in energy use or an energy reduction by a factor of 2.5.

1.) If the person needs to stay cool but an electric fan is not powerful enough, use an evaporative air cooler as opposed to a compressive air cooler. It is usually only 10% the cost of a compressive air cooler, it is portable and does not need a costly installation, and it consumes about 5% the amount of power used by a compressive air cooler. The evaporative air cooler may not be as powerful as a compressive air cooler but it is portable and can be placed near the user to directly cool their bodies as opposed to cooling their entire rooms with a standard compressive air cooler. To do a cost benefit analysis, let us assume that the person uses the compressive air cooler 24 hours a day. This type of cooler normally consumes 1000W of power so with a total power rate of $0.2/kWh, it would cost $144 to run the standard air cooler for a month. But with an evaporative air cooler the average power consumption is only 50W so in a month it would cost only $7.2 to run it. Comparing the two electricity bills there is a 95% reduction in the electricity bill and a total of $136.8 is saved a month.

2.) Install a power factor corrector in the household, preferably near the circuit breaker. This device uses new high wattage super-capacitors to store the large amounts of reactive power wasted by inductive electrical devices such as electric fans, refrigerators, and washing machines. The Power Saver brand sold in appliance stores like Ace Hardware can reduce the power wasted by electrical appliances by up to 35% and this device also serves as a lightning surge protector. The power saver brand has a maximum wattage of 3000W so make sure to buy two or more if the house's average power consumption is more than 3000W.

3.) Use low pressure sodium lamps to light the rooms because they can achieve efficiencies of 30% as opposed to the incandescent bulbs which can only achieve 5% efficiency. Also, make sure not to use an overly powerful light even if it is a low pressure sodium lamp because the excess brightness would hurt the eyes and use more than enough energy. For most private rooms, 6W of lighting using four 1.5W sodium lamps is sufficient to light the room. If the incandescent lighting is used to light a room for example, it would use 6 times the amount used by the low pressure sodium lamp equating to 36W of power. Assuming four private rooms with 24 hour usage, this is equivalent to $20.74 a month but this can be cut down to only $3.46 a month if low pressure sodium lamps are used instead. So the total energy savings is $17.28 a month.

4.) If the person is using a water heater for bathing, they should shut off the heater after use because it can consume up to 1500W of power on average because it is normally designed to heat the water in the piping of entire houses. This can cost up to $210 in one month and that amount can be reduced to $4.5 a month or less if it is only on for 30mins. or less everyday. This equates to a savings of $205.5 a month. The heater should also just be a localized heating system installed per shower because these use only 300W of power and can easily be switched off. The savings could reach $209.1 a month if such a system is used.

5.) If the person uses a water filter or cooler for their drinking needs, they should shut the device off before they go to sleep otherwise it would consume an average of 300W for a full 8 hours. That 300W of power when used for 8 hours can cost $14.4 in a month.

6.) If cellphone chargers are left connected even after the phone is charged, up to 2W of power can be used. If the family has five members using cellphones, this can use 10W of power and cost $1.44 in one month. So they should use charge timers to stop the charger when the battery is full.

7.) Use low radiation CRT TV’s because they use 58% less energy than a regular CRT TV and emit lower levels of radiation and are cheaper than an LCD TV. On average a 21” CRT is used which consumes 100W of power, the low radiation CRT particularly the ones made by Sanyo only consume 42W. With five people in the family that each have a TV, the energy cost of running the regular CRT TV’s for 16 hours a day every day is $48 a month. Using the low radiation CRT, the energy cost is only $20 so therefore the energy savings is $28 a month and $336 a year.

8.) Use a lint cleaner as opposed to a vacuum cleaner if a smooth floor that does not attract much dust is going to be cleaned. It uses no electricity and is quieter than a vacuum cleaner. Vacuum cleaners on the other hand consume 1000W on average.

In conclusion, if the energy saving methods mentioned are not used, the average middle class home can have an electricity bill of $417.12 a month. But if all 6 methods are used, the bill can drop to $510.79 and save $350.3 a month with a savings of $4,876.04 a year. In addition, the standard compressive air coolers can cost up to $700 on average but the evaporative models cost only $60 and considering that the installation costs of the compressive air cooler can reach $12 on average, the amount of money saved on initial purchase would be $652. Thus, the total savings in one year amounts to $5,528.04.

Additional Energy Saving Tips not Related to the Electricity Bill:

1.) Use sponges rather than toilet paper to clean wet surfaces because they are reusable. Using cloth will also waste energy because it is harder to clean.

2.) If the person is using an internet connection, use a small electric fan to keep the router or wireless receiver cool by blowing air at it. This will prevent it from overheating which normally slows down the internet connection or terminates it because overheating can destroy the router which will necessitate a replacement and getting the repair personnel to go to the house and change the router will use up fuel and waste the materials used to make the router. Make sure to set the fan at a low speed and place it close to the router with the thin side of the router facing the fan so that both of the wide surfaces of the router will have wind passing by them to maximize cooling efficiency.

3.) Use only tiles and concrete for the flooring and walls of the house because they are much easier to clean due to their smooth surfaces.

4.) Use an air mattress with a smooth plastic surface because it is easier to clean. The person only needs to wipe the surface with a cloth and some alcohol and the surface will be cleaned.

5.) Use a vacuum or lint cleaner to remove dry dirt like crumbs and insects. It can be done quickly so it will consume minimal electrical energy and save on water and soap.

6.) If compressible trash like paper, plastic, and tissues is being collected in a trash bag, make sure to compress the trash into a smaller volume to increase the amount of trash the bag can store. This will make the most out of the trash bag and will save on the amount of trash bags wasted.

7.) If the person's car has fuel injection and uses gasoline, buy the new E-10 fuel when refueling. It has 10% bio-ethanol mixed into gasoline and reduces harmful emissions by 10%. To add to that, ethanol is a renewable resource and makes E-10 cheaper than regular gasoline. People usually drive a total of 5,600km a month and with cars having an average fuel economy of 9km/L, 622L of fuel is used up in this duration. With the cost of gasoline at $0.8/L, the average gasoline bill would cost $497.6 a month and $5,971.2 a year. Using the E10 fuel which only costs $0.74/L, the gasoline bill would drop to $460.28 a month which equates to a 7.5% savings of $37.32 a month and a total of $447.84 a year.

8.) If the person has a garden, use only organic compost derived from bio-degradable trash as fertilizer. It is a renewable resource and is therefore much cheaper than regular artificial fertilizer.

9.) If the person has plastic, metal, and electronic waste, dispose of the waste in the nearest junk shop. They pay according to the amount of kilograms of waste products and the material waste is reused. This allows the person to profit from their garbage disposal and at the same time reduce the world's energy and fuel usage because recycling uses only 20% of the energy used by producing new materials through mining, purification, smelting and distribution.

10.) If the person frequently uses battery powered devices, they should use rechargeable batteries instead of non-rechargeable ones because they can last for 3-5 years before needing replacement. The non-rechargeable batteries can drain within hours if used for a prolonged period of time necessitating frequent replacement of the batteries if the electronic device is used often which is costly and a waste of natural resources. The person should also use a charge timer for the battery chargers because some chargers do not stop charging even when the battery is fully charged and this could overcharge the battery.

11.) When shaving, it would be more practical to use a razor with a lubricant strip because it softens the skin and prevents cuts when shaving without the aid of shaving cream. Additionally, the strip is very long lasting and uses much less resources than the traditionally used shaving cream which normally requires large amounts to be spread over the face when shaving. To make the blades of the razor perform more efficiently, remove the hairs stuck in between the blades with an old tooth brush after shaving to give the blade space to accept more hair for the next shave.

12.) After eating fruits or vegetables with seeds, the person should plant the seeds to make use of them or sell them to a grocer so the seeds can be used. This will increase crop yield and bolster the food supply.

13.) If the person has a tube containing viscous gel, like toothpaste, and the tube is empty, cut the tail of the tube to create a gaping hole and use the residue stuck to the inner lining of the tube. This will make the most out of the matter contained within the tube.

14.) To make the killing of insects more sanitary and avoid wasting disinfectants, use an electric swatter to kill insects because it uses a high voltage to burn the insect's bodies. If a regular fly swatter is used to crush the insect, the insect will spill blood and guts and the mess must be cleaned up which will necessitate the use of a disinfectant.

15.) If milk or any other drink has expired, make use of it by watering your plants with the drink rather than just throwing it away.

16.) Use dual flush toilets because they have a separate flushing mechanism for urine which saves water.

17.) Install a bidet on toilets because it uses a stream of water to wash out the fecal residue of the anus which reduces the amount of tissue paper a person needs to wipe their anus.

18.) Refill printer ink cartridges rather than buying new ones because it saves money and saves the resources used to make new cartridges.

19.) The person should use organic pesticide because it is renewable and not harmful to humans.

20.) The person should use palm oil for cooking food because it is the most nutritious cooking oil and the most abundant.

21.) If the person is using an outdoor pool, the person should put a cover on the pool to prevent debris from falling in when the pool is not in use and to decrease the time spent cleaning the pool of debris which will decrease the amount of chlorine used and the electrical energy used by the pump and siphon.

 

[G037H3]

But solar is stupid.

Spending a lot front-end and only getting your money back after a decade or two is not rational thinking.

 

[Bararontok]

That is why it is also recommended that the home owner reduce their energy consumption by switching to more efficient appliances and using appliances more efficiently to reduce energy consumption and decrease the amount of solar panels that need to be used.

 

[G037H3]

20.) The person should use palm oil for cooking food because it is the most nutritious cooking oil and the most abundant.

I guess you don't know about the massive deforestation that is taking place to make way for palm tree plantations, huh.

 

[mheslep]

Considering the fact that solar panels have a cost efficacy of $7.5/Watt,

Says who? And if you want to consider cost, why not consider the cost of equipment and installation of all the efficiency steps you recommend?

The following article posted below shows the techniques used to reduce energy consumption. With these techniques, the author of this article has reduced their energy consumption from an average of 1,200kWh/month to 480kWh/month, which is a 60% reduction in energy use or an energy reduction by a factor of 2.5. [...]

Most of those steps might be fun just to know you're being more efficient and saving a couple cents, but as a practical matter most of those items are quite silly. Without extraordinary measurement techniques, the article 'author' would have no idea how most of the low power, low duty cycle items on that list contributed to the monthly bill, as the savings would be dominated by a couple orders of magnitude by the heating/cooling steps. And even those major steps could be dominated by living in a house with one less bedroom and bath, taking one less flight per year, cutting back on a little driving, etc.

 

[mheslep]

Hi everyone,

I am thinking about getting solar power for my home in New Jersey. I was originally thinking about doing a state rebate, which would be about $5,000 off. I also saw this thing in the news about this solar company doing a $6,000 rebate, but it's a private rebate that's not involved with the state government.
http://www.prweb.com/releases/2010/09/prweb4445474.htm

Have any of you gotten any of these private rebates? Do you really get your money back, and when will you get it? Are there any other companies in New Jersey that are giving these rebates?

Thanks,

You might find this thread interesting; the OP was also in NJ and installed solar.

 

[Bararontok]

Says who? And if you want to consider cost, why not consider the cost of equipment and installation of all the efficiency steps you recommend?

Most of those steps might be fun just to know you're being more efficient and saving a couple cents, but as a practical matter most of those items are quite silly. Without extraordinary measurement techniques, the article 'author' would have no idea how most of the low power, low duty cycle items on that list contributed to the monthly bill, as the savings would be dominated by a couple orders of magnitude by the heating/cooling steps. And even those major steps could be dominated by living in a house with one less bedroom and bath, taking one less flight per year, cutting back on a little driving, etc.

Yes, but the author has not altered their living habits, only the appliances and other technologies they use, so the power saving methods actually save a large amount of money in a short amount of time and even compensate for the initial purchase cost of upgrading all of the appliances to better models.

Initial Purchase Cost of Energy Saving Items:

1.) 50W Evaporative Cooler: $60

2.) 3000W Power Factor Corrector: $40 x 2 = $80

3.) 1.5W Low Pressure Sodium Lamps (can last a whole year even if on for 24 hours a day):
$2 x 16 = $32

4.) Charge Timer: $8

5.) Sanyo 42W, 21" Low Radiation CRT: $120

6.) Lint Cleaner: $10

Total Initial Purchase Cost: $310

Total Energy Savings in 1 Year: $5,528.04

Total Adjusted Energy Savings Minus the Purchase Cost in 1 Year: $5,218.04

Profit Factor (Savings/Cost): 17.83 times the initial investment

****

Total Power Consumption of Conventional Appliances Considering the Average Amount of Appliances Needed in a Household:

1.) Compressive Air Cooler: 1,000W

2.) 16 Incandescent Bulbs: 9W x 16 = 144W

3.) 5 Conventional 21" CRT TVs: 100W x 5 = 500W

Total Power Consumption: 1,644W

Total Power Consumption of Energy Saving Appliances Considering the Average Amount of Appliances Needed in a Household:

1.) Evaporative Air Cooler: 50W

2.) 16 Low Pressure Sodium Bulbs: 1.5W x 16 = 24W

3.) 5 Low Radiation 21" CRT TVs: 42W x 5 = 210W

Total Power Consumption of the Energy Saving Appliances: 284W x 0.65 (Power Reduction Factor from the Power Saver) = 185W

Total Power Reduction Factor (Conventional Power Use/Energy Saving Use):

8.89 times lower than conventional appliances

****

Cost of Solar Panels for a Conventional Home: $12,330

Cost of Solar Panels for an Energy Saving Home: $1,387.5

 

[Ivan Seeking]

1.) If the person needs to stay cool but an electric fan is not powerful enough, use an evaporative air cooler as opposed to a compressive air cooler.

Anyone who has lived in the Sacramento valley knows that evaporative coolers are helpful, but not nearly enough on hot days. Beyond that, they don't work when there is high humidity. And I have never seen compressed air cooling used.

2.) Install a power factor corrector in the household, preferably near the circuit breaker.

Residential customers are not charged for reactive power. This is a scam.

3.) Use low pressure sodium lamps to light the rooms because they can achieve efficiencies of 30% as opposed to the incandescent bulbs which can only achieve 5% efficiency.

I need a link to the suggested lights. I don't see anything online that agrees with the information you've posted.

4.) If the person is using a water heater for bathing, they should shut off the heater after use because it can consume up to 1500W of power on average because it is normally designed to heat the water in the piping of entire houses.

Turning off the water heater won't prevent heating of the pipes. Also, it takes at least an hour to heat the water again if you want to use it. This is completely impractical.

The heater should also just be a localized heating system installed per shower because these use only 300W of power and can easily be switched off. The savings could reach $209.1 a month if such a system is used.

This would help to reduce the slight loss of energy in pipes, but you still need hot water at the faucets. Also, I would bet that heat loss in the pipes is most significant for the kitchen sink, where hot water is needed frequently for short periods of time.

5.) If the person uses a water filter or cooler for their drinking needs, they should shut the device off before they go to sleep otherwise it would consume an average of 300W for a full 8 hours. That 300W of power when used for 8 hours can cost $14.4 in a month.

Okay, I don't know anyone to whom this would apply. If you are using a water cooler and you want to reduce your bill, unplug the thing and be done with it.

6.) If cellphone chargers are left connected even after the phone is charged, up to 2W of power can be used. If the family has five members using cellphones, this can use 10W of power and cost $1.44 in one month. So they should use charge timers to stop the charger when the battery is full.

What does it cost to run the timer? I bet it cost as much as the vampire losses of the charger.

7.) Use low radiation CRT TV’s because they use 58% less energy than a regular CRT TV and emit lower levels of radiation and are cheaper than an LCD TV. On average a 21” CRT is used which consumes 100W of power, the low radiation CRT particularly the ones made by Sanyo only consume 42W. With five people in the family that each have a TV, the energy cost of running the regular CRT TV’s for 16 hours a day every day is $48 a month. Using the low radiation CRT, the energy cost is only $20 so therefore the energy savings is $28 a month and $336 a year.

Who is still using CRTs?

8.) Use a lint cleaner as opposed to a vacuum cleaner if a smooth floor that does not attract much dust is going to be cleaned. It uses no electricity and is quieter than a vacuum cleaner. Vacuum cleaners on the other hand consume 1000W on average.

Yes, or use a broom. This accounts for a few minutes worth of power a week.

In conclusion, if the energy saving methods mentioned are not used, the average middle class home can have an electricity bill of $417.12 a month. But if all 6 methods are used, the bill can drop to $510.79 and save $350.3 a month with a savings of $4,876.04 a year.

Ridiculous! Look, some of this stuff is helpful, but these numbers are pure fantasy.

 

[mheslep]

Total Adjusted Energy Savings Minus the Purchase Cost in 1 Year: $5,218.04

See this figure exceeds the cost of the total combined electric and heating/cooling load for the average (1.5KW electric load) US home, why didn't you stop and recheck your assumptions?

Edit: I see Ivan ~ beat me to it in the last sentence above.

 

[Bararontok]

Anyone who has lived in the Sacramento valley knows that evaporative coolers are helpful, but not nearly enough on hot days. Beyond that, they don't work when there is high humidity. And I have never seen compressed air cooling used.

Yes, the evaporative cooler is only truly effective for spot cooling where the cooler is directly facing the person to be cooled. In the instance that there are many people in the room, it would be more practical to use a standard compressive air cooling system that uses a compressor to drive a refrigerant such as Freon or R12 because those are more effective at cooling large areas. And for the humidity problem, the user can use a 50W automatic exhaust fan that runs for a few minutes to pump the excess humid air out of the house and automatically shuts down when the humidity drops to an acceptable level. These can be placed near windows with an insect net to block the entry of insects or the fan can be connected to a small exhaust tube which can be inserted into a small hole drilled into the wall.

Residential customers are not charged for reactive power. This is a scam.

Maybe not in America but in some countries that is the policy. That is why I did not list the average amount of money saved when the user uses a power factor corrector but even if it is slightly costly upon initial installation, at least it helps people to do their part in reducing their carbon footprint by saving inductive energy losses. This is usually impractical for power stations to do because the resistive losses incurred at long distance when the energy is sent back into the station would waste most of the energy that is going to be recuperated and the power factor correction system must be equipped with IC regulated automatic variable capacitors to automatically adjust the capacitance to exactly match the amount of energy wasted by inductors which can fluctuate because the power used by appliances can be adjusted by users and if the capacitor’s capacitance is too high or too low, energy can either be dispersed or too much can be absorbed which would still lower the efficiency of electronic devices but to implement an automatic power factor correction system on a large scale is difficult and expensive because it would require a tremendous amount of capacitors and IC circuits so an on site energy saving system is more practical.

I need a link to the suggested lights. I don't see anything online that agrees with the information you've posted.

http://en.wikipedia.org/wiki/Luminous_efficacy#Examples
1. ^ "LED or Neon? A scientific comparison". http://www.signweb.com/index.php/channel/12/id/138/.
2. ^ "Why is lightning coloured? (gas excitations)". http://webexhibits.org/causesofcolor/4.html.
3. ^ a b c d e f Philips Product Catalog (German)
http://www.lighting.philips.com/de_de/tools_downloads/pricelist_lamps/downloads/preisliste_dede_20081023.pdf

Turning off the water heater won't prevent heating of the pipes. Also, it takes at least an hour to heat the water again if you want to use it. This is completely impractical.

No, the heater should only be turned off if hot water is not needed for a very long time such as when the person is in a long sleep or if the person will leave the house for a few days.

This would help to reduce the slight loss of energy in pipes, but you still need hot water at the faucets. Also, I would bet that heat loss in the pipes is most significant for the kitchen sink, where hot water is needed frequently for short periods of time.

Well actually hot water is not really necessary for faucets because those are only used to wash hands and dishes. Even if cold water is used, as long as there is soap hands and dishes can still be cleaned but the reason why hot water has to be used in showers is because the entire body is being cleaned and if the water is cold, the person would catch a chill and may fall ill. People should actually only use a small localized heater because they only really need hot water for showers and this system is especially effective if the person is living alone and there are no other showers in the house.

Okay, I don't know anyone to whom this would apply. If you are using a water cooler and you want to reduce your bill, unplug the thing and be done with it.

Yes, but only if the person will not use the device for a long time, such as if they are going on a long sleep or leaving the house for a few days.

What does it cost to run the timer? I bet it cost as much as the vampire losses of the charger.

The timer is a spring loaded wind up timer that uses the mechanical energy stored in the spring to rotate a dial for a certain amount of time so it uses no electricity and when the dial stops turning, the relay cuts off the current to the charger.

Who is still using CRTs?

New LCD, Plasma, and LED TV’s may be more energy efficient than old CRT models but their initial purchase cost is 4 times higher than the initial purchase cost of a Low Radiation Flat CRT which is still being manufactured by companies such as Sanyo and is just as energy efficient as the new display systems. The 21” Low Radiation Flat CRT costs only $120 while the while efficient 21” Plasma, LCD and LED TV's cost $480.

Ridiculous! Look, some of this stuff is helpful, but these numbers are pure fantasy.

See this figure exceeds the cost of the total combined electric and heating/cooling load for the average (1.5KW electric load) US home, why didn't you stop and recheck your assumptions?

Edit: I see Ivan ~ beat me to it in the last sentence above.

The electricity rate factored into the calculations is not the one being used in America but is the worldwide average, so the calculations may be off by several factors. In other countries, the rate is higher because they do not use renewable energy as frequently as Americans and they do not have an abundance of oil and coal reserves. This is the reason why the savings appear higher, but in a country that has an abundance of renewable power stations that are government funded such as America and because America has its own oil and coal reserves, the electricity rate and the energy savings will of course be lower and to Americans it would not be very substantial.

Worldwide Average Electricity Rate: 20c/kWh

America's Average Electricity Rate: 6c/kWh

Note that the worldwide average and not the American average was used and this is the source of the error for the calculations.

 

[mheslep]

The electricity rate factored into the calculations is not the one being used in America but is the worldwide average, so the calculations may be off by several factors. In other countries, the rate is higher because they do not use renewable energy as frequently as Americans and they do not have an abundance of oil and coal reserves. This is the reason why the savings appear higher, but in a country that has an abundance of renewable power stations that are government funded such as America and because America has its own oil and coal reserves, the electricity rate and the energy savings will of course be lower and to Americans it would not be very substantial.

Worldwide Average Electricity Rate: 20c/kWh

America's Average Electricity Rate: 6c/kWh

Note that the worldwide average and not the American average was used and this is the source of the error for the calculations.

The total dollar figure you cited for efficiency savings is impossibly high either way. If you stay in the US then yes you get the low rate along with a high total kWh usage from extensive A/C use and large homes; if you go elsewhere the rate may go up but the average residential electricity usage is much, much lower. BTW, the US avg residential electric rate is just above 10c/kWh. US wholesale, busbar electric might be around 6c/kWh for, say, coal.

 

[Bararontok]

The total dollar figure you cited for efficiency savings is impossibly high either way. If you stay in the US then yes you get the low rate along with a high total kWh usage from extensive A/C use and large homes; if you go elsewhere the rate may go up but the average residential electricity usage is much, much lower. BTW, the US avg residential electric rate is just above 10c/kWh. US wholesale, busbar electric might be around 6c/kWh for, say, coal.

The figure was made under the assumption of extremely frequent use to the point that the appliances are all left on for very long periods of time all at the same time. This is just an estimate and not based on the real frequency of use for appliances because that can wildly fluctuate and is difficult to estimate. The savings might actually be lower for infrequent users of electrical appliances such as people who travel often or spend most of their time at work since they barely use their appliances anyway. The estimate was made on the presumption that the person is at home nearly 24 hours a day 7 days a week for a whole year.

To make a more accurate estimate, it would be more advisable to research the actual average amount of time each appliance spends running every day and the average number of times per year the appliance is used. Without more accurate data on consumer behavior, a more accurate estimate cannot be made. It is not enough just to know the difference in efficiency for appliances because the attitude of the user towards the appliances is also important.

There is even this belief among economists that if users switch to more energy efficient appliances that it would tempt them to use those appliances more frequently and that a renewable supply of resources would encourage wasteful habits and a rapid increase in population as families are led to believe that the increase in efficiency justifies having more children but this would actually cancel out the effect of increased energy efficiency. This phenomenon is called the "Rebound Effect" since it defeats the purpose of developing increased energy efficiency and renewable resources. Ultimately a simple scientific model that only accounts for technical feasibility and device performance is not really accurate in gauging energy savings so psychology, sociology, politics and economics must also be factored into arrive at more precise results.

 

[mheslep]

The figure was made under the assumption of extremely frequent use to the point that the appliances are all left on for very long periods of time all at the same time. This is just an estimate and not based on the real frequency of use for appliances because that can wildly fluctuate and is difficult to estimate. The savings might actually be lower for infrequent users of electrical appliances such as people who travel often or spend most of their time at work since they barely use their appliances anyway. The estimate was made on the presumption that the person is at home nearly 24 hours a day 7 days a week for a whole year.

Per the assumptions stated in your first post that would be not just for long periods, but left on _all_ the time, 720 hrs / month, -A/C , TVs, everything - a silly assumption.

To make a more accurate estimate, it would be more advisable to research the actual average amount of time each appliance spends running every day and the average number of times per year the appliance is used. Without more accurate data on consumer behavior, a more accurate estimate cannot be made. It is not enough just to know the difference in efficiency for appliances because the attitude of the user towards the appliances is also important

Already known. The electric load averaged 24/7 year round for US homes is about 1.5 kW. The example load for your author's case was also typical at 1200 kWh/mo or 1.6 kW average.

There is even this belief among economists that if users switch to more energy efficient appliances that it would tempt them to use those appliances more frequently and that a renewable supply of resources would encourage wasteful habits and a rapid increase in population as families are led to believe that the increase in efficiency justifies having more children but this would actually cancel out the effect of increased energy efficiency. This phenomenon is called the "Rebound Effect" since it defeats the purpose of developing increased energy efficiency and renewable resources.

That theory is known as Jevon's Paradox
http://en.wikipedia.org/wiki/Jevons_paradox

 

[Bararontok]

Per the assumptions stated in your first post that would be not just for long periods, but left on _all_ the time, 720 hrs / month, -A/C , TVs, everything - a silly assumption.

Already known. The electric load averaged 24/7 year round for US homes is about 1.5 kW. The example load for your author's case was also typical at 1200 kWh/mo or 1.6 kW average.

Yes, the assumption for the calculations is that the appliances run for 24 hours a day and this is stated in the article. Read the quote below:

To do a cost benefit analysis, let us assume that the person uses the compressive air cooler 24 hours a day.

Assuming four private rooms with 24 hour usage, this is equivalent to $20.74 a month but this can be cut down to only $3.46 a month if low pressure sodium lamps are used instead.

If the author's difference in energy is used as opposed to the extreme notion that the appliances run 24 hours a day, the savings per year is only $1,728 for the worldwide average and $995 for the American average. But even at these lower values, the Profit Factor for the worldwide average is 5.57 times the initial investment, and 3.21 times the initial investment for the American average which means that the amount of money saved in one year is much higher than the amount of money spent to upgrade to more efficient appliances.

 

[mheslep]

Yes, the assumption for the calculations is that the appliances run for 24 hours a day and this is stated in the article. Read the quote below:
If the author's difference in energy is used as opposed to the extreme notion that the appliances run 24 hours a day, the savings per year is only $1,728 for the worldwide average and $995 for the American average. But even at these lower values, the Profit Factor for the worldwide average is 5.57 times the initial investment, and 3.21 times the initial investment for the American average which means that the amount of money saved in one year is much higher than the amount of money spent to upgrade to more efficient appliances.

I don't know about the details, but ~3x sounds reasonable (before subtracting the cost of money). Now then, how does that figure compare to savings from solar panels or a solar water heater, which started the conversation?

 

[russ_watters]

While most has already been dealt with, this wasn't responded to:

Yes, the evaporative cooler is only truly effective for spot cooling where the cooler is directly facing the person to be cooled. In the instance that there are many people in the room, it would be more practical to use a standard compressive air cooling system that uses a compressor to drive a refrigerant such as Freon or R12 because those are more effective at cooling large areas. And for the humidity problem, the user can use a 50W automatic exhaust fan that runs for a few minutes to pump the excess humid air out of the house and automatically shuts down when the humidity drops to an acceptable level. These can be placed near windows with an insect net to block the entry of insects or the fan can be connected to a small exhaust tube which can be inserted into a small hole drilled into the wall.

The effectiveness of evaporative cooling doesn't have much to do with whether it is used for spot cooling or whole-house cooling. It is all a matter of the conditions of the ambient air. There are very few places in the US or western Europe where it is dry enough for evaporative cooling to work at all. Forget turning on a fan to relieve the humidity (which is silly anyway, you'd just alternate between warm and very humid and hot and humid) - you'd never get comfortable conditions with an evaporative cooler in the first place.

To do a cost benefit analysis, let us assume that the person uses the compressive air cooler 24 hours a day.

I'm not sure of the full depth of your misunderstanding, but just in case you aren't aware, even on the hottest day of the year, "using" the air conditioner 24 hours a day does not mean it is actually running 24 hours a day. On the hottest day of the year it probably runs a little more than half the time and the overall average for the summer is perhaps 1/4 of the time...and, of course, people only use it in the summer.

It is not difficult to use good assumptions here, so you really should. So let's do it:

-A somewhat larger than average house might use 4 tons of cooling or 48,000 BTU.
-Until recently, the minimum required efficiency was 10 SEER, so that's 4.8 kW.
-Most residential HVAC systems have major flaws (bad insulation, leaky ductwork, etc) so let's up that by 20% to 5.76 kW.
-Lets assume I'm home a lot and keep my house very cold, so it's on 40% of the time or 883 hours. That's 5086 kWh
-I live in Pennsylvania, near Philadelphia and my electricity is a touch above the national average at $.15/kWh including taxes and fees. So that's $763 a summer.

Depending on your climate and source of winter heat, this $763 may be the largest single chunk of a house's energy usage. If you use natural gas for heat, cooking and hot water and don't live in North Dakota, your heating probably costs a similar amount or perhaps a touch more. Then the rest of your energy needs (your TV, computer and other appliances) will cost a little less. That gives you a range of $2200 to $3000 for the yearly energy costs of a medium-large American house.

Back to the issue in the OP: obviously, you can't justify a $20,000 solar array to pay for $2000 worth of energy a year: what really can justify solar is selling the energy back to the grid when you aren't using it and selling carbon offset credits (for now and as long as they are in demand).

 

[Ivan Seeking]

3.) 1.5W Low Pressure Sodium Lamps (can last a whole year even if on for 24 hours a day):

I need a link to the suggested lights. I don't see anything online that agrees with the information you've posted.

http://en.wikipedia.org/wiki/Luminous_efficacy#Examples
1. ^ "LED or Neon? A scientific comparison". http://www.signweb.com/index.php/channel/12/id/138/.
2. ^ "Why is lightning coloured? (gas excitations)". http://webexhibits.org/causesofcolor/4.html.
3. ^ a b c d e f Philips Product Catalog (German)
http://www.lighting.philips.com/de_de/tools_downloads/pricelist_lamps/downloads/preisliste_dede_20081023.pdf

I'm asking for a direct link to a sales page for 1.5 watt low-pressure sodium lamp for the home.

 

[Ivan Seeking]

I agree that reactive power puts an extra burden on the power lines. And there are some additional I²R losses, however, we don't pay for this directly [in the US], so it isn't a way to save money, and it isn't as simple as you suggest. For example, if we live next door to each other, the reactive power from your appliances could be coupled to that from my appliances, with little reactive load seen at the local transformer.

Just FYI: In the industrial arena, we sometimes consider this in order to balance sections of a plant by reversing phase on similar machines. In this way the reactive power from two systems can cancel out. Note that these are typically three-phase systems. Industry is charged for reactive power. We also consider the higher harmonics, usually resulting from high-power switched-mode systems, which can become signficant mainly due to the total harmonic distortion produced.