Whatever your hashrate, you will only earn money when your pool finds a block. So when all the pools that you are not with are finding blocks, your own pool is eating up electricity for nothing. I noticed in some pools that it took a massive 6 hours to find a block.
Have I got this wildly wrong or should all pools integrate into one big one?
Integrating all the pools into one won't change anything because eliminating a pool does not reduce power usage. it is the miner, not the pool, that is using all the electricity.
Anyway one pool doing all the mining is bad for Bitcoin.