The Oregonian had an informative story this weekend about the prospects for converting the Boardman coal-fired power plant to burn “biomass” from plants. Many utilities are looking at replacing some fraction of their coal with plant material as a way of reducing emissions, but few have proposed anything on the ambitious scale that Portland General Electric is considering. (The utility recently announced that it would seek to either shut down the state’s only coal-fired power plant in 2020 – about two decades earlier than planned – or convert it to run entirely on an alternative fuel.)
So what kinds of plants might a former coal plant burn? The utility is looking at using wood pellets that are used in home heating stoves, which might optimistically replace 20 percent of the coal Boardman now consumes. The rest of the fuel, PGE hopes, might come from plants that are roasted at high temperatures until they resemble something like charcoal.
It’s still an experimental technology. And it remains to be seen whether PGE could get its hands on enough plant material to fuel a 585 MW power plant (about 15 percent of the energy serving its current customers.) One of the leading prospects is a tall fast-growing cane called Arundo donax that’s also used to make reeds for oboes and clarinets. It’s partial to riverbanks, sucks up a lot of water, and has become a nettlesome invasive weed in other states. But, according to the Oregonian story, the utility believes it could be farmed safely.
Still, Oregon farmers would apparently need to grow about 90,000 irrigated acres of the giant cane to serve Boardman’s needs. That’s more than all the irrigated farmland planted in food crops today in the northeastern Oregon county where the power plant is located. Needless to say, that’s a lot of giant cane, which raises big questions about whether Oregon’s farmers would embrace a new crop on such a large scale.
But that’s just one of many puzzles that the utility, regulators, power consumers and other stakeholders will be working through in the next few months, as Oregon’s Public Utility Commission decides the fate of PGE’s proposed long-range power plan.
Read more about the Northwest’s energy future in Sightline’s special series: The Dirt on Coal.