Farm Forestry New Zealand

Biomass as energy

Monday, September 05, 2016, Rik Deaton's Blog

I have a strong interest in the biomass-as-energy-source sector of renewable energy generation and I see it as inevitable that this country’s incomprehensible barriers to uptake will shortly be torn down as the many benefits that could accrue are just too compelling to be denied much longer. Those with the land to grow trees (and other biomass sources) ought to be the first to be enlightened that it is now entirely possible to burn wood (et al) with close to zero localised air pollution and that it is done to great effect and at a prodigious rate in Europe as a widely understood everyday activity. It is my strongly held opinion that every farm in this country should consider planting a mixed woodlot and/or crop of fast-grow/short-turnaround species for biomass production. Such on-farm diversification would have far reaching positive consequences in both commercial and environmental contexts but there are presently few financial incentives to do so because the market for biomass-as-energy is almost non-existent here. This is largely because forestry production in NZ is considered strictly for sawlog production and essentially ignores the local-for-local energy creation of a distributed biomass production network.

The premise of my submission to ORC was that wilding pines ought to be treated as a resource rather than as a problem; once that volte-face is accomplished the management of the trees becomes automatic and revenue positive. What has happened instead is that farmers down this way are now receiving tree eradication orders (as if it was their problem alone) and the Otago Regional Council is about to impose yet another quixotic region-wide exotic species eradication levy as part of its rates assessment because of the idiocy of the way wilding pines are to be opposed here.

The domestic supply chain for biomass based fuels (pellets, chips, firewood) is choked so the uptake of modern clean-burning biomass fired heating systems is choked ... or is it the other way around? We accept nothing prior to Euro 5 & Euro 6 vehicle emissions standards, as determined in Europe, as the acceptable benchmark under which motor vehicles can be imported into the country. However, each model of each manufacturer’s wood fired heating devices, and there are hundreds of manufacturers and thousands of devices, must be tested and certified here - “under tough Kiwi conditions” (yes, as we all know, there are no tough conditions in Europe, NZ is unique) - as opposed to simply accepting the Euro certifications they already carry as we do with motor vehicles. So guess how many manufacturers and importers are going to bother with that cost for a market of 4 million when they are already serving a market of 750 million? Is it the chicken or is it the egg? Bureaucratic stupidity on a grand scale and all that is required to fix it is a visit by someone with a functioning brain to a few Euro trade shows to see what is ?possible and what is available off the shelf to do it; or just maybe some local manufacturer could figure it out and build it here. There is some concentration on this now at the larger scale commercial end of the field but the critical domestic end is being completely blocked by our utterly invalid clean air regulations that prohibit installation on less than two hectares in most suburban areas (see attachments to understand this) and by the requirement for model by model re-certification.

So here we are with the least energy efficient residential building stock in the developed world, homes from which Central Heating Systems, considered the norm elsewhere, are totally absent, and our regulators are converting the population away from heating via a cheap renewable energy source, biomass, to heating with electricity via heat pumps, with all that implies. This, on the erroneous and invalid assumption that burning wood always causes unacceptable levels of localised air pollution. This transition is being forced by a regulatory environment that is devoid of any trace of a “shit, we got that wrong, maybe we’d better have a rethink” mechanism. The 21st century clean-burning replacement to the Model-T Ford log burners we use are staring them in the face but they ban their installation in most areas of the country.

Sporadic installation of wood gasification boilers as the heat source for modern residential central heating systems (which also provide domestic hot water as a small added side benefit!), as central heating slowly penetrates the built environment of this country, is the obvious way to gradually develop the biomass-as-energy supply chain. This self evident strategy is specifically ignored by government - I heard the Assistant Minister for the Environment say so at the “Yes We Can BioEnergy Symposium” in Wellington earlier this year ... in the same speech in which he said it was a great idea to decommission the Euro-style electric trolley bus system in the nation’s capital and replace those emission free public transport units with diesel powered buses ... but the biggest thing we could do to reduce New Zealand’s GHG emissions was to convert the nation’s car fleet to all E-vehicles.

Whilst E-vehicles are undoubtedly coming, and that is a very good thing, the Minister didn’t seem to grasp the breathtaking logical disconnect of these two positions. Such is the level of governmental comprehension of these issues; they haven’t a clue and yet they decide policy. Not a word about how all the additional E-lectricity to charge this new national fleet of E-vehicles was to be generated, not a word about energy efficiency, not a word about promoting bio-energy as he spoke at a bio-energy conference and certainly not a word (by anyone at the conference) about doing anything at all in the residential sector as the entire emphasis was on the industrial and the corporate. This despite all the pathetic PC hand-wringing twaddle about how “Kiwis are entitled to live in warm, dry, comfortable homes” (whatever that means) and how “landlords must install insulation” (whatever that means) whilst local governmental consent authorities still allow thermal energy colander homes to be built every day and national government won’t allow them to be heated in any rational manner.

The burning of biomass as an energy source will make viable the large scale planting of biomass for that purpose here in New Zealand as it has done over much of the rest of the world. This will be a valuable added income stream for farmers and it can often be accomplished on marginal or unproductive land, riparian verges, mountainsides, highway and road reserves and so on. It allows a totally different set of economic metrics to be utilised to those considered for sawlog plantations. Government, as is so often the case, simply has to just get out of the way and let it happen.

But, despite being presented with all the information they could possibly have required to take a different and far more rational direction on the issue... guess what? Yes, as I said earlier, tree eradication orders to local farmers and a new region-wide rates levy to fund fighting the good fight against the dreaded wilding pine. No strategy whatsoever for the conduct of that fight, mind you, just a hundred grand to “fight wilding pines”, then on to the next item of the meeting agenda: “how to control wintertime air pollution caused by smoking log burners in our atmospheric inversion plagued townships” ... such is the compartmentalisation of the bureaucratic mind.

So, can I distil my thirty five pages into something far less taxing to read? Well. I guess I’ll have a go here in point form:

• We, western industrial society, are addicted to energy.
• the primary form of energy, and the one that allows access to all others, is oil.
• We are at or beyond Peak Oil right now.
• There is an energy revolution happening right now and renewable technologies are finally beginning to take the high ground - very, very rapidly.
• One of the key renewable sources of energy is biomass
• Biomass is the only form of combustable energy that is renewable.
• Not only is biomass renewable but it is renewable on a human timescale and it is carbon neutral.
• One of the key areas of energy consumption is the residential built environment.
• In the order of 80% of residential energy consumption in a temperate climate is expended on heating water and on space heating and cooling.
• When one considers renewable energy strategies it is energy efficiency that absolutely must be considered first.
• The more efficient the energy consumption system the less energy must be used to operate the system irrespective of the source of that energy. Energy saved is greater than energy generated.
• The residential built environment of this country is arguably the least energy efficient in the developed world.
• The weather envelopes of our residential buildings are so porous to the passage of thermal energy - 80% of the energy we put into those building systems remember - that they fire hose thermal energy out almost faster than one can put it in.
• Our residential buildings are the literal energy equivalent of driving the family car 24-hours a day with multiple holes punched into the fuel tank.
• The residential building energy efficiency standard across the EU is about to become the German PassivHaus standard which makes PlusEnergy buildings quite possible with the addition of renewables based active systems - solar PV, solar thermal, daylighting and biomass fired heating. We are in the stone age by comparison.
• We then attempt to heat these buildings with inadequate systems that can barely keep up with the heat loss through the weather envelope.
• The very worst of these heating systems is the good old Kiwi log- burner - the Model T Ford of wood fired heating appliances.
  These appliances and their centuries old design principles combine the worst aspects a superseded technology. Incomplete combustion in a single combustion chamber due to lack of sufficient primary oxygen leads to incredibly poor thermal conversion of available calorific value in the fuel load and astonishing levels of local air pollution because of the immediate release from the flue of uncombusted but combustable gases and particulates - smoke.
  In addition, because of the crude radiant + air-to-air heat exchange mechanisms utilised by the design, the Kiwi log-burner is appallingly inefficient in thermal energy capture when compared to the pumped water jacket heat exchange system of a wood gasification boiler.
• Not sure about this? Then ask yourself why a triple-tube/double- ventilated-cavity flue system is required. Answer: to prevent the heat that should be heating your home and heating your shower water, from setting your roof on fire instead as it is flushed out into the night sky through the thermal energy super highway coming out the top of that steel box. Billowing smoke churning from the flue and circa 30-40% efficient at best compared to 96% efficiency for a wood gasification boiler emitting negligible gaseous or particulate pollution.
• Why is a pumped water heat exchanger so much more efficient? It is as simple as energy density and thermal gradient. Air and water are both fluids but water is 800 times the density of air and so has vastly superior thermal conductivity, storage and transport capability. In addition, once the air in the single room being heated by the log burner has been warmed the box is trying to get its heat output across a shallower thermal gradient. This results in overheating and efficiency reduction. The water in the pumped thermal transfer loop of a boiler always returns from the buffer tank substantially cooled and so a steep thermal gradient is maintained resulting in far superior thermal transfer at the heat source.
• The log burner also obviates the possibility of central heating and household water heating when those tasks are integral to the role of a modern wood fired boiler in Europe.
• New Zealand local consent authorities do seem to comprehend some of the shortcomings of the log-burner. They certainly understand they produce significant air pollution. What they do not seem to understand is why. Nor are they even vaguely aware that there are literally dozens of huge companies in Europe who do understand why and have developed the ultra clean burning replacement for them decades ago - the wood gasification boiler.
• There are no restrictions in Europe as to where these appliances can be installed, yet here in New Zealand, for the most part, one cannot install one at all, even though to do so would allow a family to centrally heat their home with cheap biomass, achieve close control over the temperature of each room or zone, supply household hot water and dramatically lower flue gas and particulate emissions when compared to the standard Log- burner - or to the new allegedly “clean air” log burners now being offered.
• Combine one of these boilers with some retrofitted energy efficiency measures in the building itself and the amount of wood burned can be dramatically reduced as well.
• Because our legislators apparently do not know about any of this they are currently busying themselves effectively regulating wood fired home heating appliances out of existence and insisting we turn to electricity consuming heat pumps instead. Not energy efficient ground-source (water to water) heat pumps mind you, but the cheap and nasty, far less effective and far more energy hungry single-room air source (air to air) heat pumps we think are all there is.
• Just where these geniuses think we are going to find the extra electricity to charge the batteries of a whole new national fleet of E-vehicles when we are all using all the electricity our rapidly drying out hydro lakes can produce to run heat pumps to heat our energy colander homes because we will have made heating by wood all but illegal I can’t quite discern just now. Personally, I think we need to utilise every viable renewable energy source we can find and integrate them all into a rational and planned national strategic energy policy ... but the experts know best I suppose.

Those interested enough in these musings to want to learn more about the astonishing level of maturity and sophistication of the biomass industry and the market and appliances overseas, as well as what it is that makes our homes so appallingly energy inefficient, may care to open and read the longer Wilding Pines Submission version that is attached here. Also attached here you will find information, which I can’t commend to you strongly enough, prepared by Brian Anderson of Christchurch based Bryn Martin Consulting Engineers who is vitally interested in these matters as well and has done some exemplary investigative work on the absurdly invalid, so called “clean air regulations” and how their utterly improbable outcome is to make impossible the installation of the latest generation of truly clean burning wood fired appliances here in New Zealand where they are needed so desperately.

A closing teaser to tempt you to investigate further and perhaps take some action: how big is this stuff really getting elsewhere? A recently commissioned pellet plant in the US is processing 30,000 tons a day of forestry waste and other materials. Yes these are the same pellets we buy at Mitre 10 in 20kg bags. They are shipped across the Atlantic in bulk ore carriers and used to fire power stations that have been converted from coal to biomass as their combustible fuel source. Coming soon to a location near you ... biomass fired energy production systems. All that need happen is for you to call your local member and tell him to get his absurd regulations the hell out of your way.

• Brian Anderson, graphs and data re air regs >>
• Brian Anderson - What is wrong with NZ's clean air regs? >>

Disclaimer: Personal views expressed in this blog are those of the writers and do not necessarily represent those of the NZ Farm Forestry Association.