Solar energy can be broken down into two categories; solar electric and solar thermal. Solar electric consists of photovoltaics (PV) and concentrated solar power (CSP) that produces electricity. Solar thermal technologies capture the sun’s thermal energy for water or space heating. For passive solar building design please see Publication 1293.
For basic information on solar energy energy technologies and resources please see the U.S. Department of Energy’s Solar Energy Basics website.
When considering the installation of a solar electric system or a solar thermal system on your home, there are several factors that should be evaluated, including solar access, utility cost and use, incentives and the cost of the system.
Missouri has more than 200 sunny days per year, for an average of 4.5 to 5.0 kilowatt hour per square meter per day, according to the U.S. Department of Energy’s National Renewable Energy Laboratory’s (NREL) solar maps. Missouri’s solar resources actually exceed those of Germany, which leads the world in solar energy production on less than three kWh per square meter per day.
NREL’s PVWatts is a great program for determining the solar resource at your location and the expected energy output of a solar PV system. Site specific solar access in Missouri depends on installing the system so it is not shaded by trees or other buildings. Installation may also be affected by local zoning and building permits and property owner association restrictions.
For many years the cost of electricity in Missouri has averaged seven cents per kilowatt hour ($0.07/kWh), compared to prices in the 10-14 cents range ($0.10 to $0.14 /kWh) in other parts of the country, which tempered investment in renewables. As the cost of electricity in Missouri has increased to the 10 cents range, there has been an increased demand for measures to help control the rising cost of electricity, including renewable energy and energy efficiency measures. Contact your electric provider for more information on your electric rate structure, how much energy you use and how a solar photovoltaic system could affect your monthly bill.
Based on the Solar Energy Industries Association’s (SEIA) U.S. Solar Market Insight Report Q1 2013 cost for residential installations of approximately $5.00/watt, a 2 kilowatt (kW) photovoltaic solar system that is connected to the electric grid will cost the average homeowner $10,000, and will cover part of an average annual residential electric utility load. There are several significant incentives available, which can bring down the cost of PV systems, depending on residence location. There is a federal tax credit of 30 percent of the cost of the PV system. This tax credit is available to all Missouri residences andbusinesses. For Ameren Missouri, KCP&L, and KCP&L GMO customers, there is currently a $2/watt installed rebate for systems up to 25kW. Availability may be limited so please contact your utility. Effective July 1, 2014, the rebate will be $1.50/watt. For details on these and other energy efficiency and renewable energy incentives that may be available from your utility and local, state, and federal government, be sure to check the Database of State Incentives for Renewables & Efficiency (DSIRE) and the Division of Energy’s Funding Opportunities page.
When considering a solar system, you should understand the expected performance of the solar system at your site, the local building and zoning permits, and any property owner association requirements applicable to your property. Also be aware of the net metering rules and interconnection and equipment specification requirements of your electric utility. You also may want to get installation cost quotes from several suppliers. To contact solar suppliers, please consult the Missouri Renewable Resource Directory.
Installation of solar panels (a photovoltaic or PV system) can produce numerous benefits to an individual and a community, ranging from lowered and secured energy costs to reduced environmental impact. Additional attributes of photovoltaic modules include low or zero noise, high durability and reliability, simplicity of operation, low maintenance and high power quality. The distributed nature of solar power minimizes transmission line losses, and provides maximum production at times of peak demand.
This general overview of solar energy information and the information on the linked pages above 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.