1: This is a system in preliminary design stage for a close friend. The friends farm has a natural gas well and he has virtually unlimited "free" well gas available. Location is NE Oklahoma, USA.
2: Eventual system goal is to provide all heat, cooling, and power to the farm house and large shop building 24/7.
3: The prime mover will be a modern oilfield engine (Fairbanks 118, Arrow) for reliability and supportability. The engine will drive a DC generator (watching development of options on this site) to maintain charge of a battery bank.
4: System control will be via off-the-shelf industrial PLC equipment. The engine will be automatically started/stopped as necessary to maintain battery charge. Our intention at this time is to mechanically couple a freon compressor to provide air conditioning for the house. We will be fabricating a heat exchanger to harvest waste heat during engine run and will experiment in an in-ground insulated tank for storage. The basic system logic will be based on a tiered "on-demand" operation. Sources of demand will be: electricity to charge batteries, cooling circuit, and heat. Since we have gas available for a furnace, the heat call logic will utilize the engine as a secondary source rather than primary.
Once question yet to be answered is whether the well gas flow is sufficient for continuous engine operation. We may have to add a compressor to pressurize the gas into a storage container. Details TBD.
5: development stage at this time is in the design of the system and evaluation of components. Due to the availability of the gas well, this project is worth putting a significant budget together to execute at a very high quality level. Site prep work to build the house/shop has just begun and this cogen system will be an integral part of the overall build. The owner is a master engine builder and custom fabricator with a complete machine shop, so we expect to move forward with prototype components by the end of the year with another year of iterative fine-tuning.
6: lacking any artistic creativity, we're just calling this unit "Farmpower" for now. :-)