Solar Thermal
Vs.
Solar Photovoltaic (PV)
How much is one hour of sunlight on three square meters of collector worth?
The energy from the sun varies from place to place and is dependent on local weather conditions. Without an atmosphere, 1.4 kW/m2 per hour is available. With an atmosphere we can receive 1KW/m2 per hour in the absence of clouds.
Solar Photovoltaic (PV):
If we're talking about Solar Electricity and we say that electricity is worth $0.15 per kWh than 3kWh’s are worth $0.45. The problem is that PV panels have a radiant energy conversion rate of about 20% or less so three hours of sunlight on one square meter of a solar panel is worth around $0.09
Solar Thermal:
If we're talking about Solar Thermal hot water compared to Solar Electric hot water and we say that electricity is worth $0.15 per kWh than 3kWh’s are worth $0.45. Evacuated tube collectors have a radiant energy conversion rate of about 70% to 78% depending on manufacturer and test done by SRCC. So three hours of sunlight on one square meter of a solar collector is worth around $0.32
It is clear that solar thermal is more efficient and produces more energy than solar PV:
Now, if we're talking about Solar Thermal versus other fuels we need to convert Kilowatt hours into Btu’s.
1kWh is equal to 3,412 Btu so than 3kWh’s are equal to10,236 Btu or 10.2 kBtu.
If we say 1 gallon of propane costs $3.00 and produces 91.5 kBtu per gallon than propane costs $0.033 per kBtu. ($3.00 / 91.5)
With a 70% conversion factor three hours of sunlight on one square meter of solar thermal collector will produce
7,165 Btu’s or 7.2 kBtu saving $0.24 worth of propane. ($0.033 x 7.2)
You can do some calculations on your own. Just add in the cost of fuel in your area. Here is some rough data.
The energy from the sun varies from place to place and is dependent on local weather conditions. Without an atmosphere, 1.4 kW/m2 per hour is available. With an atmosphere we can receive 1KW/m2 per hour in the absence of clouds.
Solar Photovoltaic (PV):
If we're talking about Solar Electricity and we say that electricity is worth $0.15 per kWh than 3kWh’s are worth $0.45. The problem is that PV panels have a radiant energy conversion rate of about 20% or less so three hours of sunlight on one square meter of a solar panel is worth around $0.09
Solar Thermal:
If we're talking about Solar Thermal hot water compared to Solar Electric hot water and we say that electricity is worth $0.15 per kWh than 3kWh’s are worth $0.45. Evacuated tube collectors have a radiant energy conversion rate of about 70% to 78% depending on manufacturer and test done by SRCC. So three hours of sunlight on one square meter of a solar collector is worth around $0.32
It is clear that solar thermal is more efficient and produces more energy than solar PV:
Now, if we're talking about Solar Thermal versus other fuels we need to convert Kilowatt hours into Btu’s.
1kWh is equal to 3,412 Btu so than 3kWh’s are equal to10,236 Btu or 10.2 kBtu.
If we say 1 gallon of propane costs $3.00 and produces 91.5 kBtu per gallon than propane costs $0.033 per kBtu. ($3.00 / 91.5)
With a 70% conversion factor three hours of sunlight on one square meter of solar thermal collector will produce
7,165 Btu’s or 7.2 kBtu saving $0.24 worth of propane. ($0.033 x 7.2)
You can do some calculations on your own. Just add in the cost of fuel in your area. Here is some rough data.
There is no dispute that solar PV has grown faster than solar thermal in the United States. Why? We think there are three basic reasons.
1) More and better financing for PV than solar thermal:
Banks and venture capitalists have loved solar PV for quite some time, and the reason is that solar PV projects are profitable with solar power purchase agreements (PPAs).
Solar PPA’s for solar PV are a win-win. They provide low-upfront costs to the customer while also reducing energy costs. At the same time, banks and financiers are able to recoup profits over time by capturing all of the available solar incentives, plus charging the customer a discounted rate for the power that they consumer.
What’s odd is that solar thermal applications have not attracted the same win-win attention from banks and finance people. Just as with solar PV, it’s possible to meter and measure solar hot water production and reduce the gas utility bills of large commercial applications, such as hotels, condos, apartment buildings, hospitals, laundromats, nursing homes, and so much more.
The bottom line is that bankers and other financiers need to become better informed about solar thermal applications, economics, and to develop more ways to finance projects.
2) More and better subsidies for PV than solar thermal:
Clean solar energy is clean solar energy, and yet governments seem to be more amenable to subsidizing solar electric clean energy than solar water heating applications. If you run down the list of all of the subsidies available on the DSIRE database, you'll find many more—and richer—solar PV subsidies than for solar thermal.
Once again, we think the reason behind this tilt against solar thermal is the lack of awareness and understanding from legislators about the benefits of solar thermal applications. From hot water and heat, to air conditioning, solar thermal installations could be saving consumers, businesses, and government facilities thousands of dollars over the system’s lifetime. In large installations, hundreds of thousands of dollars.
Environmentally, solar thermal can not only reduce our dependence on fossil fuels, but also decrease the current trend in hydrofracking, a process that may not only damage the environment, but also contaminate drinking water.
The solar industry needs better solar thermal lobbyists. Lobbyists are a dirty word, we know, and yet, they are effective of getting in front of legislators and explaining the benefits of solar.
3) Subsidized low gas prices:
Subsidizing the exploration of gas and other fossil fuels are not helping any consumer or business to consider purchasing renewable solar PV or solar thermal.
It’s hypocritical for Federal government to say that it wants to move the nation towards clean, renewable, non-polluting energy while encouraging the development of natural gas, enabling natural gas prices to remain artificially low. Meanwhile, utilities are raising their coal-fired electric rates between 3% and 5% a year, making solar PV increasingly competitive.
I’m not saying that gas won’t play a role in our nations near-term energy portfolio, but the sooner our legislators encourage more renewable solar alternatives by leveling the playing field and eliminating gas subsidies, the more solar jobs will be created, and of course, the more energy independent our country will be.
Once again, the solution is better solar thermal lobbying. Solar PV and wind companies all have policy people who are constantly talking to legislators. Solar thermal needs that same face-to-face representation.
1) More and better financing for PV than solar thermal:
Banks and venture capitalists have loved solar PV for quite some time, and the reason is that solar PV projects are profitable with solar power purchase agreements (PPAs).
Solar PPA’s for solar PV are a win-win. They provide low-upfront costs to the customer while also reducing energy costs. At the same time, banks and financiers are able to recoup profits over time by capturing all of the available solar incentives, plus charging the customer a discounted rate for the power that they consumer.
What’s odd is that solar thermal applications have not attracted the same win-win attention from banks and finance people. Just as with solar PV, it’s possible to meter and measure solar hot water production and reduce the gas utility bills of large commercial applications, such as hotels, condos, apartment buildings, hospitals, laundromats, nursing homes, and so much more.
The bottom line is that bankers and other financiers need to become better informed about solar thermal applications, economics, and to develop more ways to finance projects.
2) More and better subsidies for PV than solar thermal:
Clean solar energy is clean solar energy, and yet governments seem to be more amenable to subsidizing solar electric clean energy than solar water heating applications. If you run down the list of all of the subsidies available on the DSIRE database, you'll find many more—and richer—solar PV subsidies than for solar thermal.
Once again, we think the reason behind this tilt against solar thermal is the lack of awareness and understanding from legislators about the benefits of solar thermal applications. From hot water and heat, to air conditioning, solar thermal installations could be saving consumers, businesses, and government facilities thousands of dollars over the system’s lifetime. In large installations, hundreds of thousands of dollars.
Environmentally, solar thermal can not only reduce our dependence on fossil fuels, but also decrease the current trend in hydrofracking, a process that may not only damage the environment, but also contaminate drinking water.
The solar industry needs better solar thermal lobbyists. Lobbyists are a dirty word, we know, and yet, they are effective of getting in front of legislators and explaining the benefits of solar.
3) Subsidized low gas prices:
Subsidizing the exploration of gas and other fossil fuels are not helping any consumer or business to consider purchasing renewable solar PV or solar thermal.
It’s hypocritical for Federal government to say that it wants to move the nation towards clean, renewable, non-polluting energy while encouraging the development of natural gas, enabling natural gas prices to remain artificially low. Meanwhile, utilities are raising their coal-fired electric rates between 3% and 5% a year, making solar PV increasingly competitive.
I’m not saying that gas won’t play a role in our nations near-term energy portfolio, but the sooner our legislators encourage more renewable solar alternatives by leveling the playing field and eliminating gas subsidies, the more solar jobs will be created, and of course, the more energy independent our country will be.
Once again, the solution is better solar thermal lobbying. Solar PV and wind companies all have policy people who are constantly talking to legislators. Solar thermal needs that same face-to-face representation.
Copyright © 2011 Solar Dynamix