By Seth Masia
SOLAR TODAY deputy editor
Respect! The mainstream press, and culture, has finally begun to acknowledge the maturity, and viability, of solar power.
Latest example is this story from CNN, acknowledging that rooftop PV does better than grid parity, at the retail level.
At least it does in markets with tiered or time-of-use pricing, where rates can go to 40 cents per kilowatt hour (ckWh) for big consumers on summer afternoons. Running an air conditioning system from a PV array, at a levelized cost of 10 or 15 ckWh, should be a no-brainer. Here and now.
Truth is, if you look at average residential retail electricity rates and average PV prices, solar is at grid parity now even without tiered pricing. Here's the math:
Average home burns 900 kWh per month at 11 ckWh means an electric bill of $100 per month.
To offset 900 kWh per month you'd need a PV array of 5.5 kW. At today's competitive pricing ($5 per watt) that's $27,500. Straight-line amortization of that over the 25-year life span of the modules and the system costs $92 per month. You're already making money without accounting for tax credits or utility inflation.
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Comments (8)
A standard day or location for US solar
The US solar industry (or possibly the Dept of Energy) should define a standard solar day as x hours of sun per day. Or the amount of sun a house in "x" location recieves on average. (I leave it to the industry to select a reasonable value for 'x') It would then be easy to discuss and compare system performance and pricing for the average day or average location.
This would help the consumer buy a system since they could know that their solar day was 85% or 110% (or whatever %) of the standard day; or that they get 15% more sun or 10% less than the average location. Therefore they should expect to get "y"% more (or less) power out.
At least I think this would be helpful if the industry wants to sell systems across the whole country rather than in a select few states.
This would help the consumer buy a system since they could know that their solar day was 85% or 110% (or whatever %) of the standard day; or that they get 15% more sun or 10% less than the average location. Therefore they should expect to get "y"% more (or less) power out.
At least I think this would be helpful if the industry wants to sell systems across the whole country rather than in a select few states.
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July 30, 2010
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Viability of Solar
It seems like we face a similar battle in South Africa - I run a small company called Solar Science (http://www.solarscience.co.za) and we're looking to install solar water heaters at the moment. The maths stacks up so much in favour of doing this, and yet people balk at the upfront capital investment. One solution might be to put together a finance package for people, but at the moment the interest on that kind of unsecured lending is about 22% per annum!
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August 02, 2010
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Standard solar day?
Disdaniel, the National Renewable Energy Lab has defined standard solar days for all parts of the United States. A national average is more or less useless for calculating performance at any given spot -- it's not even very useful for making economic forecasts. You can see the maps and insolation tools from NREL and DoE here: http://www.nrel.gov/gis/
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August 02, 2010
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Seth,
You misunderstand me, I'm not suggesting a national sunlight average--I agree that would be useless; I'm suggesting a national standard. The difference is that a standard can include more information than just average sunlight in one location and more useful information for the buyer of solar. The map you linked to tells a potential solar buyer nothing about the cost of solar in their location. The solar standard I'm discussing would help vendors to easily link the performance of their equipment in one environment/location to customers across the country. Let's just say that the "standard day" equals 4.7 hours of sun/day (plus a bunch of other useful information like when in the day/year its cloudy and modifiers for high/low temperature). Now someone living in region x that gets 5.4 hours of sun/day can just know that he/she will get 1.15 as much as the standard.
You misunderstand me, I'm not suggesting a national sunlight average--I agree that would be useless; I'm suggesting a national standard. The difference is that a standard can include more information than just average sunlight in one location and more useful information for the buyer of solar. The map you linked to tells a potential solar buyer nothing about the cost of solar in their location. The solar standard I'm discussing would help vendors to easily link the performance of their equipment in one environment/location to customers across the country. Let's just say that the "standard day" equals 4.7 hours of sun/day (plus a bunch of other useful information like when in the day/year its cloudy and modifiers for high/low temperature). Now someone living in region x that gets 5.4 hours of sun/day can just know that he/she will get 1.15 as much as the standard.
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August 02, 2010
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(Post continued)
Someone living in in region y that gets 4.2 hours/day will get 0.9 as much as the standard.
This becomes useful because vendors can advertise their panels at say $2/standard-day watt (nationwide). Customers in region y will know that buying 1000 standard watts of solar panels will produce 900 watts in their location (1000 x 0.9). Meanwhile the customer in region x understands that they will get 1150 watts/days if they buy 1000 standard watts of solar panels (1000 x 1.15).
Someone living in in region y that gets 4.2 hours/day will get 0.9 as much as the standard.
This becomes useful because vendors can advertise their panels at say $2/standard-day watt (nationwide). Customers in region y will know that buying 1000 standard watts of solar panels will produce 900 watts in their location (1000 x 0.9). Meanwhile the customer in region x understands that they will get 1150 watts/days if they buy 1000 standard watts of solar panels (1000 x 1.15).
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August 02, 2010
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Understood, but the potential customer can already figure out what a given panel will produce at a given location just by using one of the online design tools. Moreover, the national average is generally understood to be 4.8 sun hours per day, but that seriously misstates the economic value of a technology that achieves its best power output precisely in step with the grid's peak load. It would be politcally and economically counterproductive to promote that low-ball average as a national standard.
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August 04, 2010
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25 years.
Love the equation, but that's cause I'm all for solar. I've been researching and putting together a series of articles on the subject and the problem with $92 a month, at least from what I've run into, is that it's for 25 years. I just spoke with a senior economics professor who told me the average person is in a home for 6 years. So, why invest for the person who moves in after me? Sure it'd be the nice thing to do, but nice doesn't effect wallets. People make investments all the time, but not that long.
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August 04, 2010
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"the national average is generally understood to be 4.8 sun hours per day"
I've never seen this "understanding"...in print..anywhere...ever...and I've been looking/reading industry publications for a decade
The point to my comment was to NOT make "the potential customer can already figure out what a given panel will produce at a given location just by using one of the online design tools"...rather my idea is to give them a simple measure that they can add or subtract 5, 10, or 20% (depending on location) to see how much power/cost they can expect.
(It is clear you don't agree with me, but do you have to put my idea down?)
I've never seen this "understanding"...in print..anywhere...ever...and I've been looking/reading industry publications for a decade
The point to my comment was to NOT make "the potential customer can already figure out what a given panel will produce at a given location just by using one of the online design tools"...rather my idea is to give them a simple measure that they can add or subtract 5, 10, or 20% (depending on location) to see how much power/cost they can expect.
(It is clear you don't agree with me, but do you have to put my idea down?)
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August 04, 2010
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Seth Masia
Liz Merry
