This is way we sale solar hot water not, Residential solar PV economics
SOURCE: truthaboutenergy.com
PhotoVoltaics
Let's look at the economics of putting a 2.3 kWe solar PV
system on the roof of a home. With a big splash roof top solar PV homes
are now being sold as of January 20,2007 in Roseville California
Nation's largest solar community to debut. The advertisement in the newspaper
says the owner can sell the excess electricity back to the utility and also reap
benefits of having their own electricity . After you read what I have written below
you will see that the advertisements are completely false. There will be no excess.
But so what, there are no guarantees that the solar systems will generate anything.
The Table below presents the lifetime financial duration of the PV system for 30
years of cost data. The state rebate is $2.50 per Watt. The loan term is 30 years. The
system capital cost is $20,000 and the Federal tax credit of 30% is limited to a tax
credit of $2,000. The state rebate is thus $2.50 per watt times 2,300 watts = $5,750
.The total amount financed by the owner is:$20,000 - $5,750 - $2,000 = $12,250
The home owner can finance the $12,250 for 30 years at 6.2% or 4.10% effective
mortgage rate after deduction for interest. This assumes the homeowner is in the
34% combined federal and state income tax bracket. The annual cost of the
mortgage is $710, the annual amount of electrical energy generated is 3,022 kWh,
the current cost of electrical energy to the homeowner is $0.0798 and I assumes that
it escalates 3% per year. The saving in electrical energy payments the first year is
thus 3,022 kWh x 0.0798per kWh = $241. But the first year's net cash flow to the
home owner is minus $469.
PG&E tells me that the annual usage of electrical energy varies, but 10,000 kWh is a
good number for residential homes with a 2.3 kWe solar PV system on their roof top.
Thus the solar PV system would supply about 3,022 kWe/10,000 = 30% of the
homeowners electric energy.
Financial data over 30 years of a 2.3 kWe capacity solar PV system installed on a
residential home
Year Annual Savings Net Cost Cost of Energy
Payments per Year per Year 3% Escalation
per Year
2007 $710 $241 ($469) $0.0798
2008 $710 $248 ($494) $0.0822
2009 $710 $256 ($480) $0.0847
2010 $710 $264 ($465) $0.0872
2011 $710 $271 ($450) $0.0898
2012 $710 $280 ($435) $0.0925
2013 $710 $288 ($419) $0.0953
2014 $710 $297 ($402) $0.0981
2015 $710 $306 ($385) $0.1011
2016 $710 $315 ($368) $0.1041
2017 $710 $324 ($350) $0.1072
2018 $710 $334 ($331) $0.1105
2019 $710 $344 ($312) $0.1138
2020 $710 $354 ($293) $0.1172
2021 $710 $365 ($272) $0.1207
2022 $710 $376 ($251) $0.1243
2023 $710 $387 ($230) $0.1281
2024 $710 $399 ($208) $0.1319
2025 $710 $411 ($185) $0.1359
2026 $710 $423 ($162) $0.1399
2027 $710 $436 ($137) $0.1441
2028 $710 $449 ($112) $0.1485
2029 $710 $462 ($87) $0.1529
2030 $710 $476 ($60) $0.1575
2031 $710 $490 ($33) $0.1622
2032 $710 $505 ($5) $0.1671
2033 $710 $520 $24 $0.1721
2034 $710 $536 $54 $0.1773
2035 $710 $552 $84 $0.1826
2036 $710 $568 $116 $0.1881
Summatio $21,300 $11,474 ($7,117)
Conclusions: Notice that for 32 years the homeowner has a
negative cash flow. The home owner has only four years out
of thirty where there is a positive cash flow.
The final sum over thirty year was a loss of $7,117
Daily Performance of a typical solar PV system.
Summer Time
The date is August 3, 2005
A sunny day, very little cloud cover.
The amount of energy generated is 12 kWh. More than twice the winter amount of generated energy. At
0.0798 cents per kWh of avoided energy this would save the home owner is:
0.0798 cents per kWh x 12 kWh = 96 cents
During July the generated energy from this system was about 18 kWh. One can see the difference that
the daytimes of the year makes. Still the total energy generated is quite small for the capacity and cost
of the installation. It is apparent that solar PV systems will not be significant players in the energy
picture. Before State subsidies the cost of the system is about $60,000.
I do not care what you buy as long as you know what you get.
Referrals available for installation & service technicians, countrywide.


Most RecentMost Recommended Comments (1)
at 20:08 on June 4th, 2008
This is Servamatic solar test center were Harvey Anderson and Byard D. Woods now Professor and Head Mechanical & Aerospace Engineering Department UTAH STATE UNIVERSITY worked on solar hot water and PV. Harvey said make it last.
Easy to install units!
Had to have a performance that others should be judged!
Over 80,000 systems already installed in
California, Arizona, Texas, Florida, New Mexico, Alabama, Nevada , Louisiana
Passive solar hot water heater is maintenance free.
Simplicity makes it a excellent
solar pre heater for any existing water heater. With two 316L stainless steel tanks,
over all solar hot water capacity is increased by 50 gallons.
No more running out of hot water.
Call Randy Anderson
800- 468-8420
http://servamaticsolarparts.com/index.html
http://www.dannysvacuumshop.com/solarhotwaterindex.html