To work out how much you will save on your energy bill, you first need to work out the right system size for your needs. As discussed above, you save money by offsetting the amount of electricity you are buying (self-consumed energy) and by selling electricity for a feed-in tariff. There are different rates for buying and selling energy, so understanding how much solar energy you will be self-consuming is important in estimating your savings. Simple solar payback period free calculator using the Solar Choice advanced calculator. We have created the below five scenarios that look at the savings from different system sizes with some typical assumptions made on energy consumption. We suggest you have a play with one or both of our free to use calculators: Easy to use the calculator Advanced calculator for more precise results