By Aric Saunders, Executive Vice President for Sales, Electriq Power
At the beginning of May, areas of California lifted restrictions on solar and storage installers, deeming them “essential workers.” With the majority of the state’s homeowners under stay-at-home orders during the pandemic, the necessity of reliable home power has become abundantly clear. As California prepares for wildfire season and Public Safety Power Shutoffs that will leave many in the dark, renewable energy solutions that include home battery backup systems are more important than ever to keep homes and businesses safely powered.
The California Public Utilities Commission requires that electric utility companies develop and submit plans to reduce the risk of fire ignitions caused by overhead facilities located in high fire-threat areas during an extreme wildfire event. Utility companies are faced with the challenge of protecting the stability of the power grid, while also taking into account the safety of their customers and employees. Damaged power lines or transformers can lead to loose power cables or explosions that are extremely dangerous, making it necessary to completely shut off the power so that firefighters, police department personnel, and other safety crew members can safely work to control any resulting wildfires.
PG&E, one of the largest natural gas and electric companies in the United States, has adopted the Public Safety Power Shutoff (PSPS) plan as part of their Community Wildfire Safety Program. In an extreme fire hazard situation, it may be necessary for PG&E to disconnect the power lines that serve that area. The PSPS program applies for all electric lines that are located within high fire-threat areas; however, customers located outside of these areas should still plan to take precautions.
If the power lines affected by a wildfire are at the distribution level, then the impact on the grid should be minor. However, if the area includes transmission lines, the impact on the industrial, commercial, and residential sectors in a large area could be dramatic, with the possibility of affecting millions of customers on the PG&E power grid.
Power outages can result in substantial losses in both the commercial and residential sectors. The best way to prepare for contingency situations is to have a readily available backup power resource. Solutions like fuel-powered backup generators only work during the contingency event, and are dependent on a fuel supply that could run out before power returns. As an alternative option, battery-based solutions integrated with renewable energy can protect against both unexpected and programmed shutoffs.
Bright outlook for solar power
COVID-19 has had an inevitable impact on new project deployments and the renewables supply chain. According to IEA’s Renewable Market Update report, renewable capacity additions this year are set to total 167 GW. Although this represents a 13% decrease compared to last year’s record level of installations, overall global renewable power capacity is still expanding, driving unprecedented demand for energy storage, and a projected 6% growth in 2020. Solar energy provides the most eco-friendly solution for powering appliances in homes and commercial businesses while increasing homeowner independence from the grid. However, solar energy is by definition intermittent, and therefore less reliable, without a complementary energy storage system.
The amount of energy that a solar system produces varies depending on meteorological conditions. Therefore, the stability of a PV system is reliant on a secure connection to the power grid. Grid-tied solar power systems can reduce electricity bills as the generated solar energy is consumed throughout the day. However, solar generation has a particular bell-shaped curve that does not match high-energy consumption hours.
Solar power that is not consumed during the day needs to be exported back to the grid through an energy meter under a feed-in tariff (FiT) or net metering (NEM) scheme. Unfortunately, compensation for the solar energy fed back to the grid is often well below the retail electricity rate. The ideal solution to increase revenue from solar is to optimize self-consumption, which is easily done with a backup battery.
In the non-NEM tariff example below of a residential solar + storage system in San Francisco, self-consumption of solar kilowatt/hours is maximized for a reduced energy bill and optimal ROI.
Time to talk TOU tariffs
Almost every U.S. state has implemented time of use (TOU) tariffs (with the exception of Montana and Rhode Island). These pricing schemes are related to different electricity rates across the day that increase or decrease in value based on the general congestion of the power grid at different points in time. Generally, evening hours have higher electricity rates because of the elevated demand.
In a home equipped with a grid-tied PV system without battery backup, the array will generate solar power during the day when TOU rates are low. Any excess solar energy generated by the PV system will have to be exported back to the grid at a low price. When electrical loads begin drawing power at night, electricity rates will increase significantly, resulting in a much higher price for every kWh consumed.
However, a grid-tied system with battery backup is able to store the excess solar energy generated during the day. The extra solar power in the batteries will discharge overnight to avoid energy consumption during peak electricity rate hours. This effect is called peak-load shifting.
Battery backup for energy independence
Natural disasters are one of the most common causes of grid failures in power systems. Because grid-tied PV systems depend on the grid itself to operate, they are not able to deliver power as long as a blackout lasts. As soon as the system’s inverter detects the absence of the grid frequency, the inverter’s automatic switch deactivates the DC/AC signal conversion, preventing the PV system from continuing to run. However, by installing solar PV with an energy storage system, the inverter is able to detect the absence of grid frequency, disconnect, and generate its own frequency to run the PV system and power selected loads in off-grid mode.
This wildfire season, more people than ever will be working from home and require a reliable source of power. Beneficially, California offers some of the most lucrative solar incentives in the country. By installing a battery backup system tied to solar PV, homeowners can optimize their electricity consumption and safely power their homes with clean energy during outages.
Aric Saunders is the Executive Vice President of Sales and Marketing at Electriq Power, a California-based supplier of a home energy storage solution, the PowerPod.