There are multiple types of solar energy systems that can be used to generate electricity, heat water, and heat indoor spaces. First to note is a passive solar heating system. This system uses properly-oriented, south-facing windows to collect solar heat during cooler, winter months. The heat is then trapped in the building by well-insulated walls, ceilings, and floors usually made at least partially of stone, brick, or tiles. This system does not require any extra machinery, and a passive house uses on average a fifth of the energy of the average US household! California is a great place for this more low-key type of solar heating system as we have much milder weather and rarely need robust heating.
Another type of solar heating system is an active heating system. An active system pumps heat-absorbing liquid such as water or antifreeze through roof-mounted solar collectors and then pumps this liquid either directly to faucets and showers (if the liquid being used is water) or into insulated containers filled with water, gravel, clay, or another heat-absorbing compounds where it can then be transported to radiators throughout the building to heat different rooms. The advantages of active and passive solar systems are that they are fairly inexpensive to install, are more environmentally friendly than fossil fuel burning furnaces and boilers, and can save you a lot on your heating and electric bills over time. The disadvantages? You need sunlight for at least 60% of the day for these systems to work effectively and will likely still need to install a back-up heating system for overcast and foggy days.
One common type of electricity-generating solar system is a solar-thermal power system which collects and concentrates solar heat/energy to boil water or another type of heat-transfer fluid to produce steam. This steam is then converted into mechanical energy via a turbine which powers a generator that then produces electricity. California hosts several large solar-thermal power plants including the largest solar-thermal power plant in the world, the 399 MW Ivanpah Solar Power Facility located in the Mojave Desert. This project produces enough energy to power over 140,000 California homes every day. Scientists estimate that the world’s energy needs could be met using solar-thermal energy systems and high-voltage efficient electrical grids by covering only 1% of the world’s deserts (about the size of Wisconsin) in solar panels.
“This project produces enough energy to power over 140,000 California homes every day.”
Solar panels like the ones you can install on your home, school, or business’s roof to generate electricity for personal use function very differently from solar-thermal systems. Solar panels generate direct-current (DC) electricity from the excitation of electrons in the silicon wafers that make up the panels when they are hit by sunlight. This DC energy is then converted into AC energy by a solar inverter, and the AC energy is directly fed to the building's switchboard where it can then be distributed and used by energy-requiring appliances. These small-scale solar systems can be connected to the electric grid or not although most homes/businesses/schools do not produce enough energy from their solar installations to meet all of their energy needs and therefore need to be connected to the grid in order to receive supplementary energy.
These four solar systems: passive heating, active heating, solar-thermal power, and solar panel, are the four main solar systems used by solar power systems and for heating and electricity in homes and other buildings.
"The Different Types of Solar Systems." SOLARQUOTES. Accessed May 14, 2020. https://www.solarquotes.com.au/good-solar-guide/system-types/
"Ivanpah." BrightSource Limitless. Accessed May 14, 2020. http://www.brightsourceenergy.com/ivanpah-solar-project#.XsTE45NKjBI
"Solar Explained: Solar Thermal Power Plants." US Energy Information Administration. Accessed May 14, 2020. https://www.eia.gov/energyexplained/solar/solar-thermal-power-plants.php
Fosdick, Judy. November 11, 2016. "Passive Solar Heating." Whole Building Design Guide. https://www.wbdg.org/resources/passive-solar-heating