Is it better to invest in a solar battery or more solar panels?

As the popularity of batteries in solar systems continues to surge, their prices have dropped significantly over the years. With a payback period of around seven years, it's now more feasible to include a battery when building a new house or undergoing a substantial renovation. By integrating the battery into the overall cost, you can create an ideal system without feeling the financial strain. Alternatively, if you're primarily considering solar and your financial situation allows, opting for a larger system with high-efficiency panels and spare roof space can allow you to export excess energy during the day, generate income, and use that revenue to cover your nighttime electricity usage. This approach keeps you battery-ready while taking advantage of potential future reductions in battery prices.

However, it's crucial not to install inefficient panels with low wattage, such as 270, 280, or 290-watt panels, as this may limit your options for future expansion and adding a battery. Instead, invest in efficient panels that maximize energy generation and leave room for future system upgrades. Though slightly more expensive than older technology, choosing efficient panels now ensures a smarter, future-proof investment.

\- Batteries are becoming now much more popular. We have seen the numbers grow literally by hundreds of percent from three or four years ago, the price has dropped. We are still looking at about a seven-year payback, so if I would build a new house, I'd say I just put the battery in it already at the same time, make it part of the overall cost. You won't feel the pain, and you've got possibly the ideal system. If you renovate, and again, it's a solid renovation and you think of putting solar on it at the same time, I would also just put the battery and get the one solution. On the other hand, if you're just thinking about solar and the financial situation, it might be worth put a big system on, high-efficient panel, keep bit of spare roof space and export during the day, and then make money and then use that money to bring the electricity in at night and pay for it that way, and then have it battery ready. 

So you buy the right panels and you buy the right inverter that has batteries that can be connected to it later. And I would say in two, three years time, battery prices will have come down quite a bit again and that's the same time when you go in and maybe put a couple of extra panels, and put the battery in at that time. So you can either do the one stage now and bite the big bullet, or you can do two stages. But the most important thing is do not put a 270, 280, 290-watt panel on your roof because if you don't have a mansion, you will go back to it and you go, "Oh, now I want a battery and I need a bit more grunt." And suddenly go, "Oh, I've got to expand my system." And you actually put an inefficient panel on it and you have no more roof space. So if you put an efficient panel on right now and play for spare roof space to later expand in the future, you'll be actually doing the smarter thing. They're a little bit more expensive, the older technology's much cheaper, but you're actually future-proofing your investment.