Wed 27 Aug 2008
Home Solar Panel Cost Analysis
Posted by Jason Morgan under Energy, Technology
Home solar panel systems, both off- and on-grid systems, are becoming more readily available to consumers through both increased supply and a growing market from environmental awareness propaganda. For years, people have debated the cost/benefit of solar panels for energy production with the general consensus being that traditional means of energy production are far more cost effective (previously with little concern given to the environmental impact of said energy production). With that said, it is difficult to find good, solid numerical figures to perform a cost analysis for home solar panel systems.
The variety of available home solar panel systems today is vast. Multiple manufacturers, types of panels, on- or off-grid, roof or ground mounts, and other factors all play into the cost of a solar panel system. This analysis used several core inputs:
- On-grid system (off-grid requires additional cost of battery system)
- Roof installation (ground installations are typically more expensive due to mounting)
- Total system cost has been reduced by the $2,000 Federal Tax Rebate available in 2008
- A rebate is given by your local energy company (estimates used from Planit Solar)
Before the cost is addressed, the production efficiency should be discussed. While manufacturers do not all have the same kilowatt-hour (kWh) production per square foot of solar panels, the range is fairly consistent. The two manufacturers included in this analysis range from 1.6 to 2.0 kWh optimal energy production per square foot each month. Take out your energy bills for the last twelve months and you can divide your kWh usage by 1.5 (for conservatism) and this will tell you how many square feet of solar panels you would need to power your home. This is important for determining an overall system cost for your projected solar panel system, but it does not factor in to the figures that will be discussed shortly because the analysis focuses on cost per kWh, which effectively equalizes solar panel systems of all sizes.
For a solar panel system to power a home that averages 1,000 kWh usage per month (understanding seasonal issues are averaged in to control for air conditioning and other such circumstances), the total system cost is projected at approximately $50,000. This is a hefty price-tag for a system that does not produce very much energy. However, consumers have the ability to take out long-term financing with similar interest rates to mortgages, therefore the possibility of this investment amount is within reach.
The total system cost is enough to turn most people off from this idea. Upon further analysis, the total cost of the system becomes irrelevant. The type of solar panels being discussed have a minimum of a twenty-five year guarantee, so that is the useful life over which the next number crunching exercise will take place. When one considers the total system cost divided by the total number of expected kWh produced over the life of the system, the cost per kWh ranges from $0.16 to $0.17. This is in line with energy costs from your grid. I cannot speak with for anyone but myself, however my energy costs $0.16 per kWh when you include the taxes and service charges. That puts the solar panel array at the same cost per kWh equivalent to energy from the grid provided that your system maintains optimal output for twenty-five years. This is an unreasonable assumption, so you can expect the solar panel system to cost slightly more than the grid energy.
Solar panel technology is still slightly more cost prohibitive than grid-derived energy. The gap appears to be closing, though, so environmentally-conscience and budget-conscience consumers should be on the look-out for this technology to become financially beneficial in the next few years. Remember, while the initial cost is seemingly high, the cost gap per kWh for solar panels versus grid energy is closing.
12 Responses to “ Home Solar Panel Cost Analysis ”
Comments:
Leave a Reply
Trackbacks & Pingbacks:
-
Pingback from Energy Diversity is the Solution | Atlas Editorials
September 29th, 2008 at 10:21 am[...] of the return on investment (ROI) with solar energy. Again, I will divert you to Babeled for a great cost analysis of solar power. Once solar panels become more efficient in harnessing the sun’s energy, they will be [...]

August 27th, 2008 at 10:10 pm
Jason, what is the difference between on-grid and off-grid systems?
August 27th, 2008 at 10:27 pm
From what I gather, off-grid systems require a battery system to supply energy, whereas the on-grid systems contribute directly to the grid and you still get your energy from the grid. So, with an on-grid system, when the power goes out, so does yours even though you have solar panels. The advantage is not having to pay for the battery system. No, I do not know how much that part costs, but I can try to find out.
August 27th, 2008 at 10:31 pm
Ok, so true energy independence comes from being off of the grid. Obviously that increases the amount of your initial investment. I assume the battery stores up energy for days when there is little sunlight.
August 27th, 2008 at 11:55 pm
The on-grid system I looked at costed 180K. However, there was an instant 100K rebate leaving 80K left to finance over 30 years if needed. After that there is no electric bill, only monthly payments on the investment.
Since it is an on-grid system, your meter actually spins backwards and your electric utility company pays you for the energy. The system I looked at averaged $3,000 - $7,000 per year that you get paid for. Over 30 years that is $90,000 to $210,000 which is more than enough to reimburse your 30 year loan. Also keep in mind how much value this adds to your house. How is this not a good investment again?
Put it this way, there are companies who front the expense of solar panels for corporations in exchange for a percentage of how much it will save a company in the future. Energy consulting is becoming very big because you can lock in such future contracts and then sell your company for its gauranteed future income. We just did a case study on a company like this in grad school.
Hold your horses though…because in the next 10 years, advances in solar technology will increase the efficiency of solar panel square footage by 1000%
August 28th, 2008 at 12:50 am
Now if you want a cool off-grid example, check this out!
August 28th, 2008 at 12:53 pm
The issue I see with having home solar energy is that it is difficult to forecast your energy needs. In order to be safe you must purchase a system capable of producing much more energy than you need because it is rare that your system will produce at optimal levels.
In my case, I need up to 1000 kWh on the worst summer month (central A/C is a killer) but as little as 500 kWh during the cooler months of the year. Based on the estimates from this analysis, I would need to purchase the 300 and the 900 kWh systems which would cost $67K. Almost $70k of initial investment to power a 900 sq ft apartment…that’s ridiculous.
August 28th, 2008 at 1:29 pm
I guess it would depend on how long you are going to stay at your current address. If you are picking out a home to raise a family in, it is sort of a no brainer…especially when the new solar panel shingles get 3kWh per square foot each month.
For an apartment though, you are right, it would be stupid.
August 28th, 2008 at 1:30 pm
It seems prudent to hold off for now and pursue this alternate energy option in 5-10 years when technology is better and price points come down. It probably makes little sense to be an early adopter of solar panels unless you have the money and can afford to really care about your environment.
Average income earners like ourselves will benefit from just a little bit of patience.
August 28th, 2008 at 4:03 pm
I would say if your electric bill is greater than $400 a month, solar panels make sense because that is how much the monthly payments will be when you finance the investment. On top of all the electricity you can ever use, you get paid by the electric company and your house value increases. If you electric bill is less than $300 it is probly worth the wait.
In 10 years, solar technology will render even nuclear energy obsolete. Why create plants here when the sun already does it for us? In 10 years, when solar farms are using panels that get 1000kWh, it will be something to laugh about.
August 28th, 2008 at 9:58 pm
“I’d put my money on solar energy…I hope we don’t have to wait till oil
and coal run out before we tackle that.” Thomas Edison, in conversation
with Henry Ford and Harvey Firestone, March 1931
Al Gore just quoted that during his speech at the Obama Pre-Inauguration Celebration.
August 29th, 2008 at 9:33 am
Thomas Edison, Henry Ford, and Harvey Firestone … now there is a group that didn’t accomplish much…