Here's a silly thought:

Solar panels convert sunlight into electricity. But sunlight isn't always available -- when the sun sets electricity from your solar panels runs dry. You need batteries to store solar energy when the sun is shining, and release the stored energy when the sun sets.

What batteries are to solar panels,  jam is to fruit. Strawberries don't grow throughout the year. So you take strawberries during harvest and preserve them with lots of sugar as a jam. Jams are fruit batteries, allowing us to store the energy (and nutrients) from strawberries in a form that is less ephemeral than the fruit itself.