Of course there is

. We can make maths and stats say anything we like.
£200 better return in one year sounds like a sound investment, but the downside of course is that you have lost the initial investment.
So my man maths says leaving it invested for one year gives me £10,000 + 5% interest = £10,500 in the bank
or
£10,000 - £10,000 (invested in solar etc) + £700 (£200 more than left invested in bank) = £700, equivalent of earning 7%.
Now after 1 year I have £10,500, you have £700, and if all things remained the same it would take just 7 years for my interest per year to overtake your better return of £700/year and I still have my initial 10 grand. Also in just 15 years my capital with compound interest would have become £19800 and your £700 per year would have totalled £9800, the point of equal returns apart from the me still having the initial 10k.
Different ways of seeing things and I'm sure you can display a different logic to arrive at a different outcome. As I said my heart is in solar/batteries, we don't always do things to make a financial return, but my head still says no, purely down to my low usage.