Division of Energy
Missouri’s Solar Energy Resource
Solar Energy Main Page | What is Solar Energy? | How Much Solar Energy is Available? |
How Can Solar Energy Be Used in Missouri? | Energy Efficiency |
Daylighting and Passive Solar Building Design | Solar Water Heating | Backup Systems |
Collector Positioning | Active Systems | Net Metering | Designing a System | Siting | Installation |
Solar Contacts | Solar Thermal Equipment Performance Ratings | Bibliography
A Homebuilders Guide to Going Solar (U.S. DOE brochure)
What is it, how much is there, and how can we use it?
When beginning the process of evaluating the potential of installing a solar electric system or a solar thermal system on a home or business, the factors that have to be evaluated are solar access, the utility cost, incentives and finally the cost of the system.
Missouri‘s solar resource for flat plate solar collectors is actually fairly good in comparison to other parts of the country. The National Renewable Energy Laboratory’s maps show that Missouri has between 4.5 to 5.0 kWh/m2/day. Site specific solar access in Missouri depends on locating the system so that it is not shaded by trees or other buildings.
The Division of Energy receives questions from many citizens aware of systems being installed in other parts of the country and who wonder why comparatively fewer systems are installed in Missouri. One of the main reasons is that Missouri has had a relatively low electric utility cost compared to other parts of the country. For many years the cost of electricty in Missouri has averaged around seven cents per kilowatt hour ($0.07/ kWh) compared to prices in the ten-14 cent range ($0.10 to $0.14 /kWh) in other parts of the country. As the cost of electricty here in Missouri rises there may be a rise in demand for measures to help control the rising cost of utilities, including renewable energy and energy conservation measures.
As of Fall 2008 only one Missouri utility had a small incentive for renewable energy systems. There is a federal tax credit of 30 percent of the cost of the system. Beyond these there are currently no additional financial incentives available in Missouri. These factors limit the number of Missouri residents able to afford the initial cost of a photovoltaic system. With the current installed cost of $10.00/watt, a 2 kW grid-tie system will cost the average home owner $20,000 and this will only cover part of the annual electric utility load. Depending on the size of the home and energy use, a system that will provide a net-zero energy use could run as much as $50,000.
Once in place and operating, photovoltaics and solar thermal energy collectors create no pollutants. Given that these modules typically carry warranties of 25 years and are commonly expected to remain operational long beyond the warranty period, photovoltaics contribute to cleaner energy. Additional attributes of photovoltaic modules include low or zero noise, high durability and reliability, simplicity of operation, low maintenance, high power quality, distributed nature that minimizes transmission line losses, and maximum production at times of peak demand.
This general overview of solar energy information is intended to help people beginning to think about building or buying either a photovoltaic or solar water heating system. It includes tables describing Missouri's solar resource; general explanations of passive and active solar energy systems; and bibliographical information and web links intended to lead interested parties to additional information.