A homeowner's solar experiment cut annual grid electricity use on the meter serving their water boiler from 2,100 to 800 kilowatt-hours. After that success, they turned to an online community with the more ambitious proposal of operating their solar system off-grid without batteries.

Here's what to know

The homeowner shared their setup in Reddit's r/Victron, describing seven Leapton 460-watt solar panels, an Eco-solar boost 3000 MPPT inverter, electrical protection equipment, and a three-position switch for selecting grid or solar power for the boiler.

"It was kind of an experiment to see how much energy it will save," they explained.

Together, the panels had a rated capacity of 3,220 watts. The home had two electricity meters, and the homeowner tracked the reduction on the one connected to the water boiler.

"I would like to ask about the possibility of a completely off-grid and battery-free solar system," they wrote.

For homeowners investigating the storage side of that question, EnergySage offers a resource for exploring battery products and comparing competitive installation estimates.

More background

The reported savings amounted to 1,300 kilowatt-hours annually, or about 62% of that meter's previous grid consumption., The homeowner noted autumn and winter conditions, including snow, cloud cover, and fog, affected the outcome.

The water-heating output came from an inverter, which took direct-current electricity from the panels. Their plan was to add a Victron Multi RS with two new arrays to power other home equipment. The original poster's idea to try to bypass a battery prompted red flags in the comments.

"A PV system always needs a buffer," one person wrote. "It's impossible for a PV system to constantly exactly match whatever the loads are pulling, so it needs a buffer."

Commenters recommended using batteries for the proposed off-grid system because they can act as the necessary buffer between the panels and household loads.

For homeowners weighing that expense, EnergySage has partnered with electrification company Qmerit. The partnership's goal is to help customers find the best available battery storage pricing.

What can be done?

Using solar power for a specific household task while retaining access to the grid can substantially reduce purchased electricity without requiring the entire home to operate independently.

Adding appropriately sized battery storage can extend those benefits by keeping selected household needs powered during an outage. Storing solar electricity for later use can also reduce electricity purchases and support greater energy independence, including in systems designed to operate off-grid.

"You at least need a battery to use as a sink for charge and discharge at the same time," a user explained. "A PV system output is too variable for most electronics to be happy."

After some back and forth, the original poster caught on.

"Now it is getting clear for me," they wrote. "If I read the tech doc right, the Multi RS solar (48/6000) is able to work off-grid, but needs a battery to do that."

For readers whose priority is backup power for essentials, Pila offers a plug-and-play battery alternative at a substantially lower price point than whole-home backup systems.

Where can I learn more?

Choosing whether to add batteries comes down to when you need power, whether you have grid access, and what installation will cost. 

• A solar newcomer learned how the grid covers gaps when panels operate without batteries.

• A solar buyer questioned overnight battery coverage after hearing batteries usually don't last all night.

• In Connecticut, adding batteries raised a homeowner's solar quote from $51,000 to $91,000.

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