Are we ready for the 100% renewable energy movement?

by John Ackerly, President of the Alliance for Green Heat
reprinted from Biomass Magazine

Many in the biomass heating movement bemoan warm winters, low fossil fuel prices and the slow pace of conversions to biomass heating systems.  But systems are being put in place to adopt renewable heating and that we can be part of, but we are not.

Scores of cities across the US and Canada have already pledged to go 100% renewable.  Even more will be announcing their plans in the next year or two.  Some cities are only focusing on 100% renewable electricity, but many are adopting a two stage approach.  The first stage addresses electricity needs while the second stage addresses heating.

Take Portland, Oregon, Hanover, New Hampshire and East Hampton, New York. Portland is shooting for 100% renewable electricity by 2035 and plans to tackle heating from 2035 to 2050.  Hanover is planning for 100% renewable electricity by 2030 and 100% renewable heating by 2050.  East Hampton, NY is moving even faster: 100% renewable electricity by 2020 and 100% renewable heating by 2030. Much of this heating will be fueled by electricity but chip and pellet systems could also be in demand.

A parallel trend is the Zero Net Energy (ZNE) movement.  To be considered a ZNE building, a house,  There is no one accepted definition of ZNE, so cities, campuses and communities have some leeway in how they define it.  A strict definition says biomass has to be grown and harvested on-site, but other definitions could include biomass harvested from within 30 miles, for example.  After all, the sun isn’t on-site either but the energy from it is produced on-site. 

building or campus, it cannot use more energy than the renewable energy it generates.

The point is that aggressive renewable energy strategies need to address heating and if the biomass community is not at the table, we may be left out of policies and definitions.  The Hearth, Patio & Barbecue Association has been at the table in some instances, but they are mostly fighting with the natural gas industry against gas restrictions in ZNE initiatives. 

The Biomass Thermal Energy Council (BTEC) is a natural leader for this type of advocacy, as they represent industry players that heat buildings and campuses.  This advocacy is not cheap and could easily require a full time person to engage with all the organizations and agencies involved in these movements.  But this would be an investment in the future that would pay dividends over the next 10 – 20 years. 

The renewable electricity movement is taking off because laws require utilities to sell or produce a certain percentage of their electricity from renewable sources.  The mandates typically increase until a target year, such as 20% renewables by 2020, or 25% renewables by 2025.  Legislatures can do this because state-level public service commissions (PSCs) have authority over public and private utilities.  But why don’t we regulate the heating grid the same way as we regulate the electric grid? 

Piped gas is just like electricity in many respects and is regulated in many of the same ways, but are there any gas companies required to ensure that 20% of their BTUs are renewable by 2020?  If gas companies had to install some percentage of their business as geothermal, solar thermal or biomass thermal, the renewable thermal sector would develop quickly, just as renewable electricity has.  Gas companies could install the systems themselves, just like utilities can install their own wind turbines or solar farms, or buy renewable energy credits from companies who build and operate them. 

During these Trump years, federal policy and funding of renewables will dwindle, but that is making some states, cities and campuses even more motivated to push forward.  Renewable heating is part of the equation, but are we at the table?

(This article is reprinted from Biomass Magazine.  The Biomass Magazine version had a slight error in the text.)

A reader responds to the wood vs. coal debate

In our October newsletter, we reprinted a column by Cory Hatch from the Jackson Hole News & Guide.  We found it to be a thoughtful piece by a person grappling with energy choices and trying to fairly weigh their costs and benefits.  We got a lot of positive feedback about the article but one reader, a former professor of thermodynamics thought it was important enough to clarify something the author said.

The column made many good points, and concluded:

"After you factor in the energy and associated emissions it takes to extract, refine and transport fossil fuels, wood starts to look pretty good again. If you harvest trees close to home, firewood is fairly efficient and renewable, even if storing that carbon again takes some time. Unfortunately, woodstoves have local impacts, too. Chimney smoke contains particulates, nitrogen oxides and other gasses that can degrade air quality and cause health problems, especially for people with respiratory or cardiovascular disease."

The author also noted: "according to the Sierra Club, burning coal for electricity is only about 35 percent efficient, whereas a modern wood stove is about 75 percent."

Professor Gael Ulrich took issue with that:

" It is true that wood is superior in that it is renewable and not a fossil fuel, and it does not contain sulfur or other elements that can be problems in coal stack emissions.  But his statement, attributed to the Sierra Club, implying that wood combustion is twice as efficient as coal combustion is incorrect.  The distinction is subtle and not appreciated by someone without a background in thermodynamics, but I will try to make the reason clear.  

Converting fuel energy to heat and then to electricity can never be done with 100% efficiency.  Even the most modern efficient power plants seldom succeed 40%.  Historically, that principle was elucidated by Carnot, and the theoretical maximum possible is known as the Carnot efficiency.  In short, electricity or "stored work” is a higher form of energy than heat.  Converting “heat" to “work” always represents an energy loss manifest as “waste heat.” 

Coal power plants probably don’t do much better that 35% as suggested, but wood-fired electricgenerators are even less efficient (for reasons that would require more explanation).  Converting the energy content of coal to heat can, on the other hand, be done with high efficiency, matching or exceeding that of biomass combustors.  

Thus, the statement as worded in Hatch’s column is misleading.  His arguments regarding global warming, etc. are ok.  

I thought you might be interested in the error in case someone else has not already called it to your attention."

Periodically we publish substantive comments such as this one on our blog. Scores of shorter comments are left on our Facebook site.  If you have a longer substantive comment, we can't promise to publish it but please don't hesitate to send to info@forgreenheat.org.