My Solar Potential

What are the things to need to take into consideration when planning to install solar and/or batteries?

Let’s start with a few sub-questions here:

Where can I install solar panels?

Pretty much anywhere that doesn’t receive any shading. The solar cells inside the solar panels are connected to each other in a way that causes not just the shaded cell to lose power, but almost all cells connected to it. Hence, ensure there is no shading where you would like to mount the solar panel!
You can even install solar panels behind glass windows, in houses even, but beware; you will lose efficiency. Any glass in front of the panel will reflect at least some of the sun’s rays, away from the solar cells. You want as many as possible to hit directly. That also means that placing panels in cars or houses means you don’t get any reflected sun rays, for instance from water surrounding your location. Every little bit helps!

Which direction should the panel point to?

Depends on in which hemisphere you live. Optimal direction for most of us living in the Northern hemisphere is due South. If you’re from Downunder, look North. However, East-West facing facades, roofs or balconies can also be very valuable. South facing panels produce, on average, about 16% more power than East-West facing modules.

Still, there are very good use cases for this East-West arrangement. You simply might not have any surface useful for solar facing due South. Or you might not need full power during lunch time, because you’re never home and electricity consumption is particularly low during that time of day. In that case, an East-West alignment would actually provide you with better efficiency, because that alignment optimizes production in the mornings and evenings.

Do I need to consider an angle for the solar panel?

Yup. The angle towards the sun makes a lot of difference. That doesn’t mean you shouldn’t install solar, just because you can’t get the optimal angle. That changes throughout the year, anyway. You can either set a general angle that’ll optimize production without ever changing the angle of the panel to the sun. Or you can adjust that angle at least twice a year. The difference between 0° (i.e. the panel hanging flat of a surface) and optimal angle can be 25% in production. It really depends on your location. (Yes, in actuality, it’s not quite that simple and we need to take atmospheric scattering into account – but we won’t here.)

Good solar potential calculators – we will get to those right after this – actually provide you with the ability of testing your optimal tilt (that’s what we call the angle of the panel facing the sun). Those calculators actually take weather conditions into account and you will find that you can change the angle from optimal quite a bit, before losing any noticeable amounts of electricity.

If you’d like to find just the tilt for your location, we recommend the Solar Electricity Handbook Site. This is their free Solar Angle Calculator, but if you want to get a good start in DIY Solar, buy the book. We wholeheartedly recommend it.

Kind regards,

Stephan