Solar energy is becoming increasingly widespread as the world works to move away from fossil fuels. Solar is the cleanest and most abundant renewable energy source available, with more energy from the Sun hitting the Earth in just one hour than is used by everyone in the world for an entire year. Over the last decade, the solar market has grown at a rate of 33% each year, with more than 130 GW of solar panels having been installed in the US, enough to power 23 million households. Some of the main reasons industries, businesses, and homeowners are switching to solar include diversifying their energy sources, improving their efficiency, and saving money. It is important to understand the fundamentals of solar so you can feel empowered to join the renewable energy movement.
There are three main ways to harness solar energy: photovoltaic (PV) systems, solar heating and cooling, and concentrating solar-thermal power (CSP) systems.
PV systems get their name from the photovoltaic effect, or the process of converting light (photons) into electricity (voltage). PV cells absorb sunlight and use that energy to create an electrical current. Each solar panel has many PV cells working in unison. These cells form a solar array, which can generate enough energy to power homes, businesses, or even a portion of the electrical grid. A PV power station, also known as a solar park or solar farm, is a large-scale PV system designed to supply power to the grid. PV power stations provide electricity at the utility level, and help to support the grid and assist the country in reaching its sustainability goals. As of now, 2.8% of the power grid in the US is run using PV power stations.
Solar heating and cooling systems:
Solar heating and cooling systems harness solar energy and use it to heat water. There are three main elements involved in solar heating and cooling systems: a solar collector, insulated piping, and a hot water storage tank. The solar collector gathers heat from the sun and transfers it to water. This water then flows into a hot water tank where it can be used to provide hot water, space heating, space cooling and/or pool heating. Since water heating, space heating, and space cooling account for around 72% of the energy used in a household, solar heating and cooling can be a great option to offset electricity costs and emissions.
CSP systems use mirrors to concentrate sunlight onto receivers that collect the energy and convert it to heat, which is then used to produce electricity. The energy heats a high temperature fluid in the receiver, and the resulting thermal energy is used to spin a turbine or power an engine to generate electricity. This method is typically utilized in large power plants.
Regarding excess electricity production, customers have two options: battery storage, or net metering.
With storage technologies, energy can be collected and utilized on cloudy days, at night, or in the event of an electrical disruption. There are many types of storage devices, which you can learn more about here, but batteries are the most common. Batteries store chemical energy and convert it into electrical energy. On one hand, battery installation can be costly, yet on the other hand, your home or business gains the ability to store its own energy. This way, you will still have power in the event of an outage as long as your battery is charged, and you won’t have to deal with net-metering rules and policies, which can be complicated.
Net metering is a process in which you have the ability to sell excess electricity back to the grid. This can be incredibly beneficial, especially if your utility purchases electricity at a 1:1 rate, meaning you will get as much money back as you would have paid for the electricity yourself. When you overproduce, the solar energy that goes back to the grid helps support nearby customer’s loads. During the day, most solar customers produce more electricity than they consume. Under net metering, you can export your power back to the grid and reduce your future electric bills. Net metering can be even more advantageous if your utility offers Time-Of-Use rates. Some utilities will compensate solar owners at a higher rate for electricity produced at times of day when electricity demand is at its highest. If you can manage your electricity usage so that your array produces more electricity at these times, you will be compensated by utilities at a higher rate.
Solar has a wide array of uses. It can be used to power individual homes and businesses as well as entire power plants. When switching to solar, it is important to understand the basics of the technology so you can make the decision that is right for you and your company.