Solar Energy

This heat map of the United States is an example of the National Renewable Energy Laboratory (NREL) Solar Resource Maps.The earth’s sun makes more energy in one second than the amount six billion nuclear power plants would produce in a year. The sun is also ultimately the source of all energy supplies, except for nuclear and geothermal energy.

Maryland has plenty of solar resources to help Maryland meet its solar energy goals. On average, the State of Maryland receives 5.3 kW hours/day/square meter of solar energy.

For more information on solar resources:

Solar Energy Conversion Systems

Solar Electric Systems

This solar PV panel is made up of many individual solar cells, all of which are covered with a protective sheet of glass in a PV module or panel.
Solar thermal mass such as tile floors, Trombe walls, and stone can collect, store, and dissipate the sun’s heat.

Photovoltaic (PV) systems use sunlight to generate electricity. A PV panel is made up of many individual solar cells, all of which are covered with a protective sheet of glass in a PV module or panel. The cells are made from silicon, a very common chemical element found in sand.

In addition to the panels, a PV system usually contains an inverter to covert solar power from direct current (DC) to the alternating current (AC) of the utility grid power transmission and delivery system. One benefit of PV is that there are no electricity line losses (associated with transmitting and distributing conventional electricity from large centralized generating system over many miles to homes or businesses), which can total 8-12%.

Before installing a PV system on a home or business, it makes sense to make a home or business as energy efficient as possible so accurate PV sizing can take place. PV systems can be sized and configured to generate electricity in grid-connected or stand-alone applications. A number of online calculators can help determine the size, energy output, cost, and other parameters of a PV system.

Solar Thermal Systems

Passive solar thermal design can be used to heat homes and buildings that are designed with large areas of glass facing south to maximize “passive solar gain.” Solar thermal mass such as tile floors, Trombe walls, and stone can collect, store, and dissipate the sun’s heat.

Active solar thermal systems typically use flat plate or evacuated tube collectors that collect and concentrate the sun's heat and transfer the heat to circulating water or some other heat transfer fluid. Active solar thermal systems can provide space heating, water heating, cooling, or dehumidification.

  • Flat-plate collectors typically consist of copper tubes fitted to flat absorber plates. These collectors are typically sized to contain 40 gallons of water; two collectors provide roughly half of the hot water needed to serve a family of four.
  • Evacuated tube collectors are the most efficient collectors available, can even work well in
    overcast and humid conditions, and operate in temperatures as low as -40°F. They feature a glass or metal tube containing the water or heat transfer fluid, surrounded by a larger glass tube. The space between them is a vacuum, so very little heat is lost from the fluid.

Closed-loop systems use a non-freezing liquid to transfer heat from the sun to water in a storage tank. The sun's thermal energy heats the fluid in the solar collectors. Then, this fluid passes through a heat exchanger in the storage tank, transferring the heat to the water. The non-freezing fluid then cycles back to the collectors. These systems make sense in freezing climates.

  • The Solar Rating & Certification Corporation provides performance ratings, certifications and standards for solar thermal products, with the intention of providing guidance to consumers, incentive providers, government, and the industry.

Solar Thermal Generation Systems

Solar thermal systems can also generate electricity through technologies which take advantage of heat produced by concentrating the sun's rays onto a small location with mirrored reflectors.Solar thermal systems can also generate electricity through technologies which take advantage of heat produced by concentrating the sun's rays onto a small location with mirrored reflectors.

  • The "Stirling Dish Engine" uses concentrated solar energy to run a steam turbine much like an ordinary power plant produces electricity. The engine drives a small generator typically producing from 5 to 25 kilowatts of electricity at peak. Stirling engines, together with their solar concentrators, are small and portable and can be sited near electrical loads. The sterling engine also can be powered with natural gas or propane so energy can be produced even when the sun isn't shining.
  • Most of the world’s electricity comes from steam turbines employing the Rankine cycle using steam produced by combusting coal, natural gas or oil or from nuclear fission. The Organic Rankine cycle generator is named for its use of an organic fluid such as n-pentane or toluene that allows heat recovery from lower temperature sources such as solar thermal energy, biomass combustion, industrial waste heat, or geothermal heat.

Hybrid Solar Electric/Thermal Systems

Solar systems that produce both electricity and heated air (PV/T) can generate 2-3 times more energy than a standalone PV system.
Solar Buzz tracks PV prices, industry trends, market share, industry news, and useful facts and figures.

Solar systems that produce both electricity and heated air (PV/T) can generate 2-3 times more energy than a standalone PV system for approximately 25% more cost, according to some manufacturers. The two solar technologies in one footprint offset both heating and electricity costs, while also increasing the PV performance by up to 10% by cooling the panels.

Solar Energy Market Trends

Solar Energy Projects

Residential Systems

Nonresidential Systems

Apply for a Solar Grant

Questions?

Contact Clean Energy Program Manager Doug Hinrichs via email at dhinrichs@energy.state.md.us or phone at 410-260-7543.