I bought a few of these month by month starting September 2022, before the cold weather hit, and used them over winter. Reviewing now in April 2023. Heated 3 bedrooms 800W, 1000W, and 800W. Plus ad-hoc heating with smaller 220W and 500W panels, moving them where needed. We have not used the Gas Central Heating at all. The outcome? We have all been very warm this winter. My son sits in his room with his shirt off most of the time. Daughter has been nice and warm. I’ve been working from home with heating on day and night. Cost: Monthly bill has just gone down from £315/month to £220/month and I’m £1300 in credit – during the energy crisis!!! I think these panels have nearly paid for themselves. Will be asking for my energy credit to be refunded and will buy panels for the other rooms with it! Thanks Herschel Infrared! Very happy.