If your solar panels produce more electricity than your home uses during the day, you have several options: sell it back to the grid, store it in batteries, heat your water, charge an electric vehicle, or join a virtual power plant program. The best choice depends on how much your utility pays for exported power, because that number has been dropping fast. In California, for example, new solar billing plans value exports at roughly 75% less than the previous program did. That shift makes self-consumption strategies far more valuable than they were even a few years ago.
Why Excess Solar Is Worth Less on the Grid
Most utilities offer some form of net metering, where your electric meter tracks both the power you draw and the power you send back. At the end of a billing cycle, you’re credited for your exports. The problem is how little those credits are often worth. Under some current plans, the net surplus compensation rate sits around $0.019 per kWh. Compare that to the $0.30 or more you pay to buy a kilowatt-hour from the same utility, and the math is clear: every unit of solar power you use yourself is worth far more than one you export.
This gap keeps widening. Utilities argue that midday solar floods the grid when demand is low, reducing its value. The practical result for homeowners is that sending surplus power to the grid earns pennies, while pulling power back in the evening costs dollars. That imbalance is the single biggest reason to find ways to use your excess production at home.
Store It in a Battery
A home battery system captures surplus solar during the day and releases it in the evening when your panels stop producing. This lets you avoid buying expensive grid power after sunset, which is when electricity rates are highest under time-of-use pricing. A typical residential battery stores 10 to 15 kWh, enough to cover several hours of average household consumption.
Batteries also provide backup power during outages. Without one, your solar system shuts down when the grid goes down. This is a safety requirement called anti-islanding protection: your inverter monitors the grid’s voltage and frequency, and must stop exporting power within about 2 seconds of detecting an outage. That means a grid-tied system with no battery leaves you in the dark during a blackout, even on a sunny day. A battery with its own inverter can disconnect from the grid and keep your home running independently.
The main drawback is cost. A battery system typically runs $10,000 to $15,000 installed, though federal tax credits reduce that. Payback depends on your local rate structure, but in areas with steep time-of-use pricing, it can fall under 10 years.
Heat Your Water With a Diverter
A solar power diverter is one of the most cost-effective ways to soak up surplus energy. It’s a small device installed near your electrical panel that monitors how much power is flowing to the grid. As soon as it detects more than about 50 to 100 watts of excess, it redirects that energy to your electric water heater.
The clever part is how it handles partial loads. If you have 1,200 watts of surplus but your water heater draws 3,600 watts, the diverter cycles the heater on for one-third of the time, matching consumption to available solar power without pulling anything from the grid. Some diverters use rapid pulse-width modulation switching, which effectively acts as a smooth, proportional controller rather than an on-off switch, resulting in cleaner power delivery.
Heating water is ideal for surplus solar because a hot water tank is essentially a thermal battery. You’re converting electricity into stored heat that you’ll use later for showers, dishes, and laundry. Diverters typically cost a few hundred dollars and can pay for themselves in roughly five years, depending on how much surplus you generate and your local electricity rates. It’s a simple, low-risk upgrade that requires no changes to your existing water heater.
Charge an Electric Vehicle
If you own or plan to buy an electric vehicle, your excess solar can eliminate most or all of your fuel costs. Several smart EV chargers now offer a “solar only” mode that draws power exclusively from your surplus production. The charger communicates with your solar system (or monitors your meter) and adjusts the charging rate to match whatever excess is available.
In solar-only mode, no grid power is used at all. Charging speeds vary with cloud cover and household demand, so this works best when the car is parked at home during peak sun hours. Drivers who work from home or have flexible schedules benefit most. For those who need a full charge by a specific time, some chargers offer a hybrid mode that prioritizes solar but tops off from the grid if needed.
The economics are compelling. Charging an EV from solar costs nothing per mile, compared to roughly 4 to 5 cents per mile on grid electricity or 10 to 15 cents per mile on gasoline. Over the life of a vehicle, that adds up to thousands of dollars in savings, all powered by energy your panels were going to give away for nearly free.
Join a Virtual Power Plant
Virtual power plants, or VPPs, are programs that pool the batteries and solar systems of many homes into a coordinated network. When the grid is stressed (typically on hot summer evenings), the program operator dispatches stored energy from participants’ batteries to help meet demand. In exchange, you receive credits, bill reductions, or direct payments.
The U.S. Department of Energy has been funding VPP pilot projects across the country, noting that participants benefit from lower electricity bills while also earning additional rewards for the grid services their batteries provide. Some programs offer upfront incentives like discounted battery installations, while others pay per-event or per-kilowatt-hour dispatched.
Participation typically requires a compatible home battery and a smart inverter. You set preferences for how much stored energy you’re willing to share and how much you want to keep in reserve for your own backup needs. The grid operator handles the rest automatically. It’s a way to monetize your battery’s capacity during the hours when it would otherwise sit idle.
Shift Heavy Loads to Midday
The simplest strategy requires no new equipment at all. Running your most power-hungry appliances during peak solar production, roughly 10 a.m. to 3 p.m., means that energy gets consumed on-site instead of exported. Dishwashers, washing machines, dryers, and pool pumps are all good candidates. Many of these appliances have delay-start timers built in.
This approach won’t capture all your surplus, but it’s free and immediate. Even shifting one or two large loads into the solar window can meaningfully reduce what you send to the grid. Pair it with a programmable thermostat that pre-cools your house in the early afternoon, and you’re effectively storing solar energy as cool air before evening rates kick in.
Thermal Storage for Heating and Cooling
Beyond hot water tanks, newer thermal storage systems use phase-change materials integrated with your home’s HVAC system. These materials absorb heat as they melt (similar to how ice absorbs heat as it melts) and release it later when you need it. Research from the National Institute of Standards and Technology has found that integrating phase-change materials with residential air conditioning can reduce energy use by 6% to 33%, depending on the design.
These systems are still emerging in the residential market, but the concept is straightforward: use your cheap midday solar to “charge” a thermal storage unit, then draw on that stored heating or cooling in the evening. It’s the same principle as heating your water tank, applied to climate control. For homes in extreme climates where HVAC is the biggest electricity expense, this approach could eventually rival batteries in cost-effectiveness.
Combining Strategies for Maximum Value
Most solar households get the best results by layering several of these approaches. A typical setup might look like this: a diverter handles the first few hundred watts of surplus by heating water, a smart EV charger absorbs a larger block during the middle of the day, and a battery captures whatever remains for evening use. Load shifting fills in the gaps with no added cost.
The priority order generally follows the economics. Using power yourself is worth the full retail rate you’d otherwise pay, so self-consumption always beats exporting. Within self-consumption, the highest-value use is whatever displaces the most expensive energy. If you’re on time-of-use rates, that’s typically evening electricity, making battery storage especially valuable. If your rates are flat, a diverter or EV charger may pay back faster because the hardware costs less.
Start by checking your utility’s current export rate. If it’s anywhere near the $0.02 per kWh range, every kilowatt-hour you keep at home is saving you 10 to 15 times what you’d earn by sending it away. That ratio makes almost any self-consumption investment worthwhile.