Can you draw power from your solar system when the sun isn’t shining? If you have a way of storing the electricity the system has produced you can. Batteries have long been used for solar power storage, but haven’t been popular until recently. With Tesla Motors announcement of a new battery for residential solar storage, it may be within the reach of many solar system users soon.
In the 1970’s, the early days of solar photovoltaic systems, solar power was mainly used to bring electricity to places that could not be reached by the grid. So to ensure that power was available continually, batteries were hooked up to the solar power systems. This allowed systems to store solar power during peak production periods (when demands for electricity were lower than what was being produced) and feed it to the building when the system was not producing power.
Commercial Solar Power, Net Metering and Solar System Upkeep
But as solar energy systems became a popular option for those with access to the grid, the development of systems that don’t need a battery moved ahead. The majority of residential or small commercial solar energy systems in the U.S. today are connected directly to the grid and therefore don’t need a way to store energy by themselves. For most solar energy users, their relationship with the grid is governed by a policy called Net Metering (NM). NM allows users of solar energy to consume the power that they create first, if more power is needed it is fed from the grid. If excess power is produced, your meter runs backwards.
As solar power becomes more popular, utility companies argue that those who use it under a net metering policy aren’t shouldering their share of the cost of grid upkeep. Utilities are increasingly turning to base fees for those who use solar, or raising rates for all customers to make up the difference. As utilities go through the growing pains of adjusting to a systems which includes more distributed power producers, having a source of power totally independent of the grid becomes more attractive.
How Your Batteries, Generators Will Impact Your Solar Photovoltaic System
Batteries for residential solar photovoltaic systems come in all different types of technologies, but as lithium-ion batteries have been refined in electric cars they and lead-acid (like the battery found in a typical car) have become the most popular option.
Adding a battery to your solar system can be an expensive proposition. According to a 2013 report commissioned by NYSERDA adding a battery to your system could “double the PV hardware cost but its impact on the total installed cost [would be] about 25 – 30%, depending on [the battery’s] capacity and capabilities”
But as the technology is refined by companies entering the market, expect those prices to fall. Tesla Motors recently announced Tesla Energy, a residential solar storage system battery, and a financing plan for adding that battery to your system. In addition to Tesla, several large solar installation companies have partnered with firms that develop battery technology in a bid to enter the solar storage marketplace.