The amount of sunlight that strikes the earth's surface in an hour and a half is enough to handle the entire world's energy consumption for a full year. Solar technologies convert sunlight into electrical energy either through photovoltaic (PV) panels or through mirrors that concentrate solar radiation. This energy can be used to generate electricity or be stored in batteries or thermal storage.
Below, you can find resources and information on the basics of solar radiation, photovoltaic and concentrating solar-thermal power technologies, electrical grid systems integration, and the non-hardware aspects (soft costs) of solar energy. You can also learn more about how to go solar and the solar energy industry. In addition, you can dive deeper into solar energy and learn about how the U.S. Department of Energy Solar Energy Technologies Office is driving innovative research and development in these areas.
Solar radiation is light – also known as electromagnetic radiation – that is emitted by the sun. While every location on Earth receives some sunlight over a year, the amount of solar radiation that reaches any one spot on the Earth’s surface varies. Solar technologies capture this radiation and turn it into useful forms of energy.
Even the most ardent solar evangelists can agree on one limitation solar panels have: they only produce electricity when the sun is shining. But, peak energy use tends to come in the evenings, coinciding with decreased solar generation and causing a supply and demand issue. The thing is, solar panels often pump out more than enough energy during those lower demand hours when the sun is shining to meet peak demand later in the day. This means that efficient solar energy storage can open up a wealth of possibilities for homeowners and businesses alike.
In this blog, we’ll look at solar energy storage in-depth, its benefits, and even tools for modeling it on your solar installs.
Click above to learn more about selling solar under NEM 3.0.Storing this surplus energy is essential to getting the most out of any solar panel system, and can result in cost-savings, more efficient energy grids, and decreased fossil fuel emissions. Storing solar energy has a few main benefits:
. If electricity isn’t stored, it has to be used at the moment it’s generated. Energy storage allows surplus generation to be banked for peak-use. As far as renewable energy is concerned, storing surplus power allows the lights to stay on when the sun goes down or the wind stops blowing. Simply put, energy storage allows an energy reservoir to be charged when generation is high and demand is low, then released when generation diminishes and demand grows.
Short-term solar energy storage allows for consistent energy flow during brief disruptions in generators, such as passing clouds or routine maintenance.
The energy grid is vulnerable to disruptions and outages due to anything from wildfires to severe weather.
Solar energy storage creates a protective bubble during disruptive events by decentralizing where we get our energy from.
If you live in a state that has no solar net energy metering, or policies that don’t fairly compensate you for the solar energy you generate, battery storage can help lower your utility bills while consuming more of your own power. So, while you may not be compensated as much for excess energy sent to the grid, any additional solar power generated and stored throughout the day can be discharged from a battery at night or on cloudy days in the place of utility consumption.
Solar energy storage can be broken into three general categories: battery, thermal, and mechanical. Let’s take a quick look at each.
Batteries are by far the most common way for residential installations to store solar energy. When solar energy is pumped into a battery, a chemical reaction among the battery components stores the energy. The reaction is reversed when the battery is discharged, allowing current to exit the battery. Lithium-ion batteries are most commonly used in solar applications, and new battery technology is expanding rapidly, which promises to yield cheaper, more scalable battery storage solutions. In fact, U.S. energy storage is expected to reach nearly 7.5 GW annually by 2025, a sixfold growth from 2020, representing a market worth $7.3 billion.
Thermal energy storage uses various mediums — such as water or molten salt — to absorb and retain heat from the sun. This heated medium is stored in an insulated tank until the energy is needed, usually to boil water for energy generation.
Mechanical energy storage takes advantage of the potential energy of an object to generate electricity. Mechanical storage methods convert surplus electrical power into mechanical power, which is converted back into electricity for later use. There are three prominent mechanical energy storage systems:
This method uses surplus electricity to spin a flywheel, which later generates electricity to supply quick energy during peak demand times.
With pumped hydro, water is pumped uphill to a reservoir located above turbine generators. The water is allowed to flow through turbines and generate electricity when demand is high.
With this energy storage system, compressed air is pumped into large vessels such as a tank or underground formation. The air is released to generate electricity during peak demand.
There’s no silver bullet solution for solar energy storage. Solar energy storage solutions depend on your requirements and available resources. Let’s look at some common solar energy storage options for commercial and home applications.
Utility companies and other businesses generally have bigger budgets than individual households, making mechanical and thermal storage viable options. Though costs for these storage methods can be high, they help utilities keep up with peak energy demand.
deployed
476 MW of new storage, a 240% increase from the record-breaking previous quarter. Most of the new deployments are one-hour front-of-the-meter (FTM) storage solutions, but nonetheless offer a promising look into the future of commercial solar energy storage.
. The most
recent government estimates calculate compressed air
costs at $105/kWh, making it the most cost-effective mechanical storage option for large-scale applications.
Surplus solar energy can be used to pump water uphill, creating a massive amount of potential energy.
Current pumped hydro costs
are around $165/kWh, making it the second-best option for mechanical energy storage at scale. It’s only available in certain areas, however, as new pumped hydro involves high upfront costs and significant regulatory hurdles.
Residential solar has myriad benefits, including resiliency, cost savings, and decentralization of electrical production (otherwise known as “virtual power plants”). But the commercial energy storage methods we discussed above are likely cost-prohibitive for the average homeowner. Thankfully, battery storage can now offer homeowners a cost-effective and efficient way to store solar energy.
Lithium-ion batteries are the go-to for home solar energy storage. They’re relatively cheap (and getting cheaper), low profile, and suited for a range of needs. Other batteries commonly available for residential use include saltwater batteries and lead-acid batteries.
Regardless of the battery type, home backup batteries allow homeowners to save energy during high production, low demand times (i.e. during the workday) for use during high demand periods when generation diminishes. Home solar energy storage inherits the same benefits of large-scale solar energy storage, translating into resiliency, uninterrupted energy, and cost savings. And these benefits go directly to the homeowner.
Technology to help design solar battery storage
Designing a storage system along with a solar installation used to be labor-intensive and include a fair amount of guesswork. Now, software like Aurora‘s includes battery storage as part of its offerings.
Using Aurora Solar’s Battery Storage Tool, solar installers can analyze load off-set, calculate the projected price of a project, forecast smart battery sizing recommendations based on customer priorities, and present it to the customer in a compelling, easy-to-understand way.
Aurora has also introduced battery self-consumption modeling. You can learn more here.
So, while the technology used to store solar energy may seem complicated or overwhelming to some customers, Aurora can help you break down the complexities for customers with interactive and easy-to-understand models of performance and savings.
Click above to learn more about modeling battery storage for self consumption in Aurora.Click here to learn more about Aurora’s battery self-consumption modeling capabilities.
The sun offers a limitless supply of clean power, but harnessing it can be a challenge. Thankfully, several options for commercial and residential storage offer proven solutions for storing solar energy, and emerging technologies are being developed daily. For commercial applications, mechanical storage options provide effective solutions to harnessing solar energy when it’s needed most, and grid-scale battery storage will likely become available soon. For residential solar, battery storage is the best option, with a variety of affordable units on the market. Together, these solutions provide an effective portfolio for storing solar energy and provide a compelling argument for further solar deployment in commercial and residential settings.
To learn more, visit these resources:
To see battery self-consumption modeling in action, schedule a quick demo.