Pentland Biomass – fuel for the family and others

He said: “Our family decided to venture into using biomass boilers because, at that time, very few others were doing the same thing. The high cost of oil had increased the cost of supplying heat and hot water to our family’s five and a half acres of greenhouses, which were used to produce bedding plants. We installed a 2 MW Reka boiler and within two years we had our money back, bearing in mind this was before the time of RHI grants. Initially, we bought recycled timber to burn in the boiler but soon started to explore sourcing and producing our own timber fuel.”

As early adopters of biomass as a means to provide fuel, the Spray family found there was a lot of interest in what they were doing. Needing around 2,500 tonnes of woodfuel themselves, setting up a fuel supply chain made complete sense. Pentland Plants, as well as having its own garden centre operation on the Loanhead site, is also the largest bedding plant supplier in Scotland.

Richard’s sister Carolyn manages the garden centre, while father David and mother Hilda look after the bedding plant side of the business.

Richard’s fellow director, Shiona Macmillan, came on board 10 years ago to look at the marketing of the business. Up until two years ago, Pentland Biomass also installed both domestic and commercial biomass systems. “We installed around 400 systems ranging from small domestic ones to systems in castles, hotels, and schools,” said Richard. “Up until recently, with the RHI grants, you could make a good commercial case to a client to install a system and get a return on their investment in a short number of years. This is not so much the case now and we took the decision to pull out of installation and  concentrate on the woodfuel supply side.”

From the beginning, finding the right equipment to do the job has been part of the challenge for Richard. Once the decision was made to start sourcing his own roundwood, he opted first for a Jenz 561 chipper. He then sourced and moved on to a Jenz 581 artic trailer-mounted chipper and then one that was on a DAF B5 rigid truck, ultimately ending up with a 400 hp Mus-Max WT 10 XL trailer-mounted chipper.

The growth in Combined Heat and Power (CHP) systems created a demand for a chunkier size of woodchip. The Mus-Max chipper, which could deal with whole trees, was ideal for this job, travelling the country chipping logs for biomass. However, not long after having invested in this machine, the market was flooded with new entrants and the number of biomass installations stopped growing. This resulted in there being more of a need to use the other 400 hp Mus-Max WT 10 XL that Richard had invested in. This chipper is operated through power take-off supplied by one of two Case 400 hp Magnum 380 CVX tractors and routinely operates at the yard eight hours a day. Given that the operator needs to spend so long at a time operating the chipper, Richard ensured the cab was modified to be placed on the crane itself.

“This means the operator is in the cab, which moves in line with the crane, preventing the constant turning and straining of the operator. Also, being high up on the crane means the operator can see exactly what is going into the chipper. This helps the quality of the end product coming out, but also helps to prevent breakdowns from non-wood products being fed in.”

Richard described the Loanhead site as a windy one and good for drying timber. However, the fact that it can take a year before air-dried timber can be used to produce woodchip made investing in a drying floor an urgent requirement.

Pentland Biomass put in two drying floors, handling construction and installation itself. The floors are heated by an 800 kW Herz Biofire boiler and Lauber L-ENZ 370 dryer, which is a high-performance fan and heat-exchanger system.

“We have found out through a bit of trial and error how long it takes to dry woodchip. As we have expanded into firewood logs, we have had to work out the moisture content we require to create a great product for our customers. Oak takes a little longer to dry than other species.”

Pentland Biomass produces around 15,000 tonnes of dry chip a year, supplying hotels, estates and farm businesses as well as others. All of the wood that it uses is sourced within an hour’s drive from the Edinburgh base. It sources through supply contracts with companies such as Scottish Woodlands, Euroforest and Agriforest. This normally involves collecting at the roadside using its own fleet of trucks. Some comes through project prices and some through fixed supply contracts, from things like wind farm site clearances.

Standing sales are sometimes used as Pentland Biomass has the capability to manage this through gaining felling licences and doing the necessary planning and paperwork for the timber site owners.

“We can do everything for them and then we subcontract out the actual felling. We can remove the timber ourselves with our own transport. The amount of timber we source this way is small scale in comparison to the other methods but it allows us to plan when we do it to suit our own needs.”

Pentland Biomass currently operates a fleet of Scania R450 trucks. Richard said: “We operated DAF trucks previously but I feel the Scania truck is the truck for timber. We have had good backup from them and leasing means that we have a fixed cost per month and a service contract for each of the trucks. We replace the trucks every four years. Our latest truck, a Scania S500, arrived with us at the beginning of May.” 

The company had two turntable Robinson timber trailers, each with a Loglift 120 crane. They also have two Knapen fixed-side-wall walking-floor trailers.

“The Knapen walking-floor trailers have real heavy-duty floors, extremely robust, and ideal for what we want to use them for. We can chip directly into them without any issues. They are also lighter than other trailers in the market. This, allied to the Scania tractor units, which are also lighter, means we can haul up to one and a half tonnes more chip when we operate both of them in tandem.”

Having these trucks also means that Richard has to ensure they are kept fully utilised. This is achieved by transporting timber for other companies including Euroforest and Hi-Line. The walking trailers are used to backhaul pallets of wood pellets from Land Energy at Girvan after having delivered woodchip into them, wood pellets being another woodfuel that Pentland Biomass offers.

Richard was keen to talk about the purchase of the Tajfun (Typhoon) RCA 480 JOY firewood processor from Kilworth Machinery. This joystick-controlled machine is the largest in the Tajfun range, is able to deal with timber up to 45 cm diameter and has a 25-tonne splitting force. The processor is fed from a log loader, which pulls timber from a timber deck and the logs exit via a discharge conveyor.

“We have had the Tajfun for around eight months and it is a great machine. To increase the flexibility of it we have made it mobile, so we can hitch it up and tow it off site. The cut logs sit in a tray, which can then be opened to move them up the conveyor. There is a great uniformity to the logs produced as well as a great-quality end product. From the processor we take the split logs directly to the drying floor before they go through a log cleaner to be dropped into bags or directly into a trailer for their onward delivery.”

Pentland Biomass has a drying floor which is split into two areas, allowing woodchip to be dried on one side and logs on the other. To dry a 90 m³ artic load of logs takes around two and a half days. Firewood is dried to less than 10 per cent moisture content and around 28 per cent for woodchip. Part of any firewood processing throws up chaff and fines, which the end user doesn’t want in their firewood delivery. To ensure it is purely good firewood logs that Pentland Biomass supplies, Richard invested in a Posch LogFix XL Log Cleaner.

“Jas P Wilson had the log cleaner up at our site taking part in the Wood-Mizer Open House event back in April. Having seen it operating and how good it was getting the waste material away from the logs, I knew that I had to have it.”

This investment in new machinery has helped take Pentland Biomass to an annual firewood production total of 1,500 tonnes per year and Richard would like to see that move on to 2,500 in the coming years.

Close to the company’s main site, Pentland Biomass rents an area of land which it has turned into a log yard capable of carrying 14,000 tonnes of wood when full. On arrival, the logs are dated and placed in rows to allow tracking of how long they have been there. In the past – before the drying floor – wood would have stayed there for a year; now it can be used as required.

“We have a couple of storage bays where we can chip at the yard and in the near future the idea is to move our firewood production operation to this site where there is more space to cope with the increasing demand. We have a Wood-Mizer LT 10 sawmill and we can use it to produce either for our own use or for customers who are looking to get small runs of wood to be milled. For the bigger runs, such as the 10 x 5 sleepers we sell, we get Keith Threadgall Sawmill Services in for a day to mill them using his Wood-Mizer LT40.”

The log yard has its own weighbridge, which Richard had installed two years ago. He said: “With the number of 25-tonne truckloads of timber coming into the yard, we soon found out, using the weighbridge, that most were two to three tonnes light. Now we pay for what we are delivered.”

Pentland Biomass has become one of Scotland’s largest suppliers of woodchip in recent years and has now moved into firewood production. However, Richard is happy with the company’s current size and scale. “When we did the installations we had a workforce of around 20,” he said. “Now we are concentrating on the biomass side, this has reduced to around half that level. I don’t want the business to get too big and risk losing the personal touch, which to me is so important, but we still intend to keep moving forward.”