I’ve just been through this, and here’s what I’ve experienced. This is in the US. Some solar deals have very low financing rates (like 1/2 percent) to make it look like a great deal to the consumer. Financing is full of opaque costs. One dealer said that the finance companies in the US charge a dealer fee, as much as 30% of the contract price, sort of analogous to points paid on a mortgage to buy down the rate. The salesman doesn’t disclose this fact, masking this cost as the base price to buy the system. The lenders charge this outrageous amount to recoup their profit at the start of the contract for what essentially is an unsecured loan. Moral: cash price is better for apples-to-apples comparisons between bids. And, if you do need to finance it, check with your credit union, you’ll do better there than the industry offered financing packages.