Regarding the article suggesting that NW Natural oversold its efforts to go green, the limited availability of renewable natural gas is no secret to the industry, (“NW Natural said it was going green. It sells as much fossil fuel as before,” Sept. 13). Yet supply isn’t the only issue-the cost of renewable gas is significantly higher than the price for natural gas. Hydrogen is a less supply-constrained option that NW Natural is exploring, but it is similarly expensive. At those prices, complete conversion to renewable gas – even if possible – would cause most consumers to switch to other forms of energy of their own accord.