We are thinking GREEN and we will never use mining pools. Every day the cost of electricity to mine Bitcoins is over 30,000,000 USD worldwide which is harmful to the environment.
Pool CPU are using like 100w each .... it's nothing compared to a HD 6990 as you can use for mining in solo. So your argument about the cost of electricity are totally wrong, and thats sound very unprofessional about the devs skill, im sorry.
PS: When you are mining on a pool, it's your CPU/GPU who consumes electricity then not the pool... like i said one CPU pool consumes around 100w (150 to 350 full server), when one solo miner consumes around 300 or 10000w and more.