Waste-to-energy: HB’s organic gold?

[As published in September/October BayBuzz magazine.]

As the region grapples with its ongoing recovery from the February floods, BayBuzz is exploring possible improvements for long term resilience. Here we examine whether waste to energy solutions might be part of the basket of solutions that would see us robust and ready for future shocks. 

In the Hastings District Council’s locality plan for the recovery is a suggestion that $500,000 could be used to explore waste-to-energy solutions for the region. Unfortunately, principal advisor, district development Mark Clews says that this has not been scoped or made subject to a business case as there is yet to be any indication of support for such funding.

The thinking behind this suggestion was that if the region could become more efficient in its use of residual waste streams from forestry and horticulture, it could reduce Hawke’s Bay’s reliance on power generation from outside the region, better manage waste generated from weather events and natural hazards, and reduce the threat from forestry waste in the event of extreme climatic events, he said.

“Accordingly, a holistic review of waste to energy options with resilience at its centre may be timely as part of the longer term recovery mission. The focus here would be on dealing with organic primary industry waste and bio energy versus municipal waste and gasification, although some landfill diversion of organic residual waste (after waste minimisation efforts) as part of a holistic approach may be warranted. At this stage however, there has been no indication of support or otherwise for the initiative or likely funding sources through the recovery planning activities.”

So, consigned to the wish list?

What’s out there already that could be built on?

Reporoa sets the standard

With respect to food waste, the Bay could benefit from something like the state-of-the-art Ecogas facility in Reporoa, says director Andrew Fisher. The plant is New Zealand’s first anaerobic digestion system using food waste to generate biogas and create renewable energy and carbon dioxide, as well as nutrient-rich bio-fertiliser.

The plant, which opened last October, is a hybrid of three of the best such plants in the world. Sitting on just two hectares, it can process 125,000 tonnes of food waste a year but is only consented to do 75 tonnes. Compare that to the Bay’s BioRich, which processes 60 million cubic metres of waste, 40,000 of that in Awatoto, where they just received $1 million from the government to help get back up and running. 

Ecogas was able to arrange for the collection of about 500,000 tonnes of commercial and domestic waste in the direct aftermath of Cyclone Gabrielle, which was turned into various resources: compost, bio-fertilisers, CO2, bio-methane, truck fuel, electricity, and hot water.

Fisher reviles the term ‘waste-to-energy’, however, because to him it’s more accurately described as ‘resource recovery’. “It’s not waste to energy – it’s not. It’s circularity of the nutrition cycle. This is water recovery; food is 80% water.”

He estimates that roughly 320,000 tonnes of food waste goes to landfill each year in New Zealand. Most of it household waste. The country grows enough food for 40 million people and there is plenty of commercial waste in the supply chain.

“It’s potentially the new green gold. It is organic gold. Things like bananas and oranges all have nutrients in their skins. Those nutrients end up at the bottom of landfills instead of going back into our productivity.”

Hawke’s Bay has all the elements necessary to be able to supply a regional plant, he said. He estimates New Zealand could easily keep at least 21 plants fermenting food waste. He points to Ireland, which is a similar size and population and yet has 31 such plants with another 17 under construction, and just four landfills. New Zealand on the other hand, has one plant and 134 landfills, “because we won’t debate and talk through stuff. For some reason on waste, we want to go back and discover the wheel. We spend so much time in that space as opposed to getting on and trying to copy [what works].”

“If we were to divert all the food waste currently going to landfill in the North Island we could replace all the domestic gas use at 70% cheaper than the current price and 60% of the commercial gas use with something we have already got – that’s productivity and reduces cost of living.”

The Reporoa plant produces enough fertiliser to replace synthetic versions on 7,000 hectares of land, the energy used by 20 hectares of glass houses, and the fuel for about 20 trucks – all products that New Zealand currently imports

Ecogas is currently building a plant in Manawatū. So how would Hawke’s Bay go about getting one? The company is already servicing seven Hawke’s Bay sites daily, including meat producers, and transporting the food waste to Reporoa

“Invite us to replicate Reporoa. We’d love to do something in Hawke’s Bay. It’s got all the ingredients. The councils don’t need the money. [Ecogas owner] Central Lakes Trust has the money and the resources, but you need to engage and be welcomed on, just like with iwi or communities.

“If they open the door and said look come down [we’d be delighted]. If they go through the tender route, well why would we bother when Nelson, Christchurch and Oamaru want us to build? It’s not arrogance, it’s about certainty. We’ve got seven big Hawke’s Bay companies who would write letters of support tomorrow. It’s cheaper for them to send waste to Reporoa than to landfills.”

Fisher says Ecogas is about 25% cheaper per tonne than sending waste to landfill. Benefits from going with Ecogas, he claims, are that the money would go back into the community, they wouldn’t work against existing providers like BioRich, whereas foreign owners would have no reservations about that. 

Regarding ownership, he notes, “Councils can’t tell Blackrock what to do.” Blackrock owns roughly half of the country’s landfills. 

The other half, apart from those that are council-owned, are owned by CKI, the largest publicly listed infrastructure company in Hong Kong. And it’s the landfill operators and the collectors that present the most serious opposition to plants such as Ecogas getting a foothold across the country, Fisher says.

Waste from forestry and woody debris

Nestled above the Oh My Goodness bakery-cafe in Hastings is the tiny office of Polytechnik, a globally leading Austrian supplier of biomass combustion plants. Director Christian Jirkowsky has lived here for 16 years, but like Fisher, thinks New Zealand is far behind the curve when it comes to utilising waste-to-energy technology.

He describes how Germany and Austria have demonstrated very successfully how well it works, in terms of the amount of biomass residues they are using in their energy systems. “It’s completely mind-boggling. Austria, a country three quarters the size of the South Island is using more biomass for energy than New Zealand harvests in total, thereby having half a million biomass boilers in the country.”

Even better, he says, you wouldn’t even know they have a forestry industry because you never see clear-felled areas. “They have a forestry road network. You are only allowed to take out small numbers of trees in small areas, you are not allowed to do clear felling. Their problem is way worse, because their topsoil is gone so they can’t afford to do that. We just need to go there and see how it’s done and why and apply it here in a locally appropriate way.”

Jirkowsky is adamant about the need to stop burning fossil fuels and products like steel and concrete, and instead use wood to build our homes and buildings. He believes that New Zealand could run very well on a mix of renewable energy in 15 to 20 years. Biogas would be part of that mix, he says.

“Biogas, bioenergy is used biomass. We can use it to produce heat or power, usually a combustible gas for energy or heat and power directly. It’s a miracle really, biomass forms sugar from sunlight and carbon and then releases oxygen, which is used by us as a fuel. As we inhale, we burn it in our body and produce CO2 and get as a byproduct, energy and heat. It’s a closed loop system.”

This process is replicated in biomass boilers by taking various types of woody biomass feedstock, such as densified pellets, wood chips, hog fuel, saw dust, peelings, shredded residues, shaving, branches and twigs and bark, and using them in biomass plants. This is a great way to utilise forestry waste, but also construction demolition, he says.

These various inputs can then be used in different processes: gasification, torrefaction, carbonisation and combustion gas. From these various boiler systems, high value products like hot water, steam, thermal oil, electricity, fertilisers, syngas, biochar, bio-methane and other drop-in fuels can be generated – depending on how they are designed.

He says a region like Hawke’s Bay could be completely self-sufficient using our waste streams to produce biogas for combustion and biomass to energy systems. The region could also produce high quality products like biochar from orchard biomass. Biochar has a myriad of beneficial applications including as an agricultural fertiliser, reducing antibiotics in livestock production, and cleaning up contaminated soil as it binds to toxins. 

I asked Jirkowsky about HDC’s request for money to investigate waste to energy propositions. Had Polytechnik ever engaged with local councils or the agency? “They might have in-house experts in the field. We haven’t been asked, but if you get the right people, you should get a good understanding [of what’s possible]. The risk with funding for studies is that what happens really quickly is that large consultancies suck that up in no time and you’re left with 500 pages but not anyone to provide a resource. It just gives you another idea.”

Instead, councils or the Recovery Agency could just talk to experts already doing these things, and who are often much cheaper than a consultancy, whose business is selling their time. Most of that knowledge already exists in the community, he says.

“We know all the solutions out there and to a degree we know what all the woody resources are because of a report from SCION that looked at all the regions of New Zealand and quantified resources. If we think we would not have enough resources in the form of biomass in 10- or 20-years time, well how easy is it to just plant a tree?”

Pan Pac: technical experts?

Speaking of experts in their field, what about Pan Pac, which has been burning woody biomass for fuel for around 45 years and taking community biomass residues for burning for about 15 years.

“We have got gas onsite and we can burn a bit of gas but that was to replace the oil and really as a backup and a top up thing. We put in a second boiler some years ago increasing our ability to burn residue waste. Then we put a turbine in to make electricity out of it as well,” says fibre supply and utilities manager, Phil Hardie.

The forestry and processing company replaces about 12% of its electricity use by burning these residues for biofuel, according to its sustainability report.

“The whole woody biomass industry for energy is in a state of growth around the country at the moment. It has come to fruition over the last few years. From our point of view, we couldn’t burn a lot more than we’ve got because it would max out the capacity of our boilers and we are pretty close to that right now. Unless we put some more capacity in the plant, and that would only be used to make something like electricity. We make enough energy to dry our lumber and pulp. 

“We also have to be a bit careful because the competition for biomass is increasing and therefore the demand is growing. There is quite a lot of government money around at the moment to help you to do stuff. Organisations like hospitals and councils, schools, universities – there is funding there to help them move away from gas or coal. I think there are no schools burning coal now.”

Pan Pac, which was put out of action by flood damage, will soon be up and running again but won’t be at full capacity until March next year. It has already played a big part in collecting and stockpiling woody debris from the floods. There are a lot of clean-up locations and piles of hogged wood around the Bay at the moment, however, much of it isn’t suitable to burn in the Pan Pac boilers.

“They haven’t consulted with us first. They’ve gone and chopped it all up and it’s full of dirt and debris and most of that stuff is of no interest to us. There are quite a few stockpiles of logs around the place, and we are very interested in that and we’ll be looking to burn that if it’s not crazy pricing.”

Hardie says there is potential for Pan Pac to expand into the collection of biomass for itself and to help stabilise the industry to a degree, so as to prevent pricing from getting out of control at a time when people are getting into the business. This would depend to a large degree on the price of carbon credits and whether investors believe they are set to lose or make money. However, he warns that the volumes of biomass needed to fuel such boilers are significant. The boilers at Pan Pac take 700 tonnes a day. To put that in perspective, a cleared orchard generates only about 100 tonnes or so of woody biomass, so collection volumes will be a critical consideration.

All in all, some great options for the region worth exploring, if those in the driving seat are willing to confer with hands-on experts and think and act outside the box. Could the Bay’s voluminous biomass be turned into Green Gold? Where there is a will then there’s a way, as they say. Is there a will? 

Public Interest Journalism funded by NZ on Air