Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to create a solar panel water heater [title] Get a double-glazed unit for the sunlight to pass through. [step] Glaziers and window manufacturers sometimes have scrap units for patio doors or large windows that can be bought very cheaply. Glass with a low-emissivity coating such as pilkington k glass is ideal.

Ending1: [title] Get a single-panel room radiator that is slightly smaller than the glass unit. [step] Scrap yards sometimes have old radiators, or ask a plumber who is refurbishing a central heating system. Ending2: [title] Cut out two panels for the light fixtures in your home. [step] They should be at least 24 inches (61 cm) by 36 inches (61 cm). Ending3: [title] Decide what sizes you want your solar panels to be. [step] Some of them will be big enough that able-bodied people are able to fit into them. Ending4: [title] Find a plug-in faucet. [step] A tap with a hard rod is best, as power is concentrated in the chamber.

Answer format: ending1/ending2/ending3/ending4