What role does and will biomass play in the fuel source of tomorrow? Is it an answer to coal? Considered green energy? Sustainable?

Based on my experience biomass will continue to play a limited role. To be honest I don’t know if it is considered green (would guess no).

I can talk to one state and one state only, Michigan. Roughly 53% of the state is covered with forest. 

Pre-Covid, I was at a state conference and said that bio-mass would make a good winter fuel for electricity and heating to complement solar. The head of the Department of Natural Resources and his head forester were there and immediately jumped on my comments. Turns out that the a sustainable level of bio-mass from the just shy of 19 million acres of forest land in the state (if we stop using it for lumber, toilet paper, etc.) is about 15% of our annual electrical use, based on their internal studies. 

If we just burn cardboard, and other cellulose based post consumer products, they estimate it would be less than 7% of the state's needs. 

As to growing switch grass or other ag bio-mass the first comment is that it does not have the value per acre to displace food crops, or grazing land. The second comment was that it too would fail as the primary fuel to power the state. 

I went home after the meeting, pulled the MISO data for our zone, pulled the forest yield per year in our USDA zones, and other numbers and did a massive spread sheet. They were somewhat optimistic on what bio-mass could power in Michigan. 

You are welcome to generalize as you see fit. 

As I read these answers, I am drawn to one thing: There are passionate opinions on both sides, but there is no simple answer. Larry Eisenberg makes his case that biomass is the very definition of sustainability and is answered by Bob Meinetz and Andrew Blakers as the very definition of "un-sustainability", with solid reasons to back it up. 

Then along comes John, Mathew and Roger with more on the topic and great references to boot. That is what I had hoped would happen, but let's not stop there. Let's learn more and come to an Energy Central consensus about it. I like the analogy that it is simply another solar option, just using old growth stored carbon that can't sustain our planet let alone our energy needs. Interesting. 

Contrary to the views of some of the folks answering this question, biomass is the very definition of sustainability.  Cut it down and use it and more grows to replace the material taken.  This contrasts with the fossil fuels and nuclear fuel that have a very finite presence on Earth.  At some point all of the fossil fuels and likely radioactive material suitable to produce energy will be fully consumed. The fundamental issue / question about biomass is how it is used.  If it is just burned as has been done for centuries, we get climate change.  If it is processed in a high-tech manner, where products are produced and there is no off-gassing, then it becomes a very effective tool for energy production and needed by-product supply.  One other point is that sustainably managed forests to offer an excellent option for carbon capture.  Sustainably managed forests, with the undergrowth removed, offer the best resistance to fire. A proactive program to remove that undergrowth from all forests will produce a vast quantity of biomass.  Current practice has been to simply burn it.  Instead, technology is now available to very effectively utilize that material in a very effective, non-polluting manner.

The growth in the use of biomass for energy production and other production of other needed products in growing a very rapid pace.  New technology and new companies are springing up almost daily focusing on effective use of biomass.  Most of the major fossil fuel providers know this to be the case and are making large investments into biomass-based technology to change from a fossil fuel company to an energy company.  The potential change that we will see in this industry is really quite unlimited. 

Biomass (apart from genuine waste) is a wretched energy source.

The solar-to-electricity or solar-to-motive energy of biomass is in the range 0.1-1%. Solar PV efficiency is 20%. Thus, solar uses 20-200 times less land than bio for the same energy service.

Bio competes with food production and ecosystems for land, water, pesticides and fertilizers.

The only large-scale biomass system for removing carbon from the atmosphere that is sustainable is restoration of complex ecosytems on former farmland. Large amounts of carbon can be stored above and below ground for centuries - provided the trees are not cut down.

Hi Alan:

Good Answers below.

I've written several posts on using biomass for generation. I'll point you at three of these.

The first is an early post, which I'll send you to, since our Almond Orchards have just finished blooming:

The second post covers the first method of using biomass - direct combustion with carbon capture and storage (CCS):

https://energycentral.com/c/cp/new-networks-part-3-two-solutions

And the final one defines a second method that describes what is probably the best method: convert either non-woody biomass to biomethane using anaerobic (without oxygen) digestion / fermentation, or woody biomass to syngas using pyrolysis, and then methanation of the syngas to produce biomethane. Biomethane can use the normal gas pipeline to travel to a normal combined cycle plant, preferably one with CCS.

-John

Hello,
I have spent a few years building prototype small scale decentralised biomass generators, based on Brayton cycle and using hot air as working fluid, operating as a gas turbine generator.
The technology would be ideal for a northern region looking to replace coal combustion with decentralised biomass fired plants on an intelligent grid.
Further, such decentralised plants can be placed closed to residential or agricultural sites that require heat energy, allowing the biomass energy usage to reach 95%.
Such plants can have an ROI in less than 3 years, and with correct maintenance, produce for decades.

There is certainly a major role for biomass in a sustainable energy future. Just how big that role will be, what the sources of biomass will be, and how the biomass will be processed are more difficult to predict. But if nothing else, BECCS (biomass energy with CCS) is almost certainly the most cost-effective way to remove CO2 from the atmosphere. It can't scale to the level ultimately required, but it can help.

Some sources of biomass for energy are relatively non-controversial. Urban green wastes, agricultural wastes, food wastes -- no controversy about using them, but some about the best way to do so. Choices are anaerobic digestion for production of biogas and reclamation of nutrient content; low temperature pyrolysis for production of hydrogen and volatile hydrocarbons, with activated biochar as residue; aerobic digestion for production of ethanol and a nearly pure CO2 waste stream; oxy combustion for maximum power generation, an easily captured CO2 waste stream, and nutrient mineral salts reclaimed from ashes. And when all else fails (or is deemed too expensive) rapid high temperature composting for low grade space heat and soil enhancement. Using sawdust, bark, and wood chips from lumber production to make wood pellets is also relatively non-controversial. Somewhat more controversial, but finding growing acceptance, is forest thinning and clearing of underbrush for fire prevention. Generally opposed are energy crops grown on agricultural land in competition with food crops. Really awful but still big business is clearing of rainforests to plant palm oil plantations for production of "carbon neutral" aviation and diesel fuels.

Unfortunately, the profitability and business case for the various alternatives is more or less proportional to the environmental harm they do.