PDCs are PRECISION DRY Wood Chips:
PRECISION: Because we take in standard random sized green, mostly hardwood chips and put them through a screening process that filters out chips that are too large and re-chips them. Our goal is to have chips about the size of a standard match book–fairly regular in size and shape so they can be transported easily using augers and blowers.
DRY: The green wood chips that we make PDCs out of arrive with moisture contents of between 35% and 55%. Once they go through our processing, they have an assured moisture content of 25%.
Download the Froling Energy PDC Specifications Brochure
WHY PDCs? They are the middle ground in biomass fuels: PDCs burn better and cleaner than green chips in boiler systems that are much less costly to build. On the other hand, Pellet Boiler systems are less costly to build than PDC systems, but as a fuel, PDCs cost 35% less than wood pellets. In mid-sized boiler systems of between 1/2 and 4 million BTU/hour it doesn’t take too many years for a PDC boiler system to make up that difference. PDC boilers are simply a better investment.
You might wonder how it is possible to store PDCs in an outdoor steel silo, “Won’t they freeze up in winter and compost in the summer?” No they won’t! We have found that with their 25% moisture content, PDCs do not freeze to each other into immovable blocks inside of silos, even in -20 degrees. They also will not generate the high composting temperatures that green chips can climb to in the summer. With the quality control employed in making PDCs, there’s nothing to worry about.
How do PDCs compare to green or raw wood chips? Green chips cost less per ton, but the with a natural moisture content of between 35% and 55% you’ll need as much as 50% more tons of green chips to be able to generate the same amount of heat as PDCs. (Water doesn’t burn and must be boiled off–using more energy) The initial system and infrastructure costs required to handle burning green chips are much higher than what is required for PDCs. This includes large, covered concrete pits and ESPs (Electrostatic Precipitators) required for pollution control. The more highly sophisticated boilers that we use for burning PDCs don’t require ESPs to meet smoke stack regulations.
How do PDCs compare to wood pellets? Blower truck delivery into vertical silos is the most important similarity. While a wood pellet silo can be a fairly long way from the pellet boiler, PDC storage bins need to be fairly close to the boilers that they feed using rigid augers. PDCs are not as energy dense as wood pellets–in fact they take up more than twice the volume of storage space for the same BTU value– and the future fuel savings make any additional investments very worthwhile. Here’s an interesting fact: All of the boiler systems that we set up to burn PDCs can also burn Wood Pellets.
DOWNLOAD THIS CHART that compares the initial and ongoing fuel costs of 4 different boiler systems: 3 types of biomass fuels, all for a hypothetical school using 50,000 gallons of fuel oil. Future Cost Predictor–Project + Fuel with RECs HYPOTHETICAL SCHOOL
How do PDCs compare to Fossil Fuels? They cost a lot less!! By themselves PDCs have a net cost equal to Oil at $1.28 a gallon.
But when the generation of New Hampshire Class 1 Thermal RECs (or Mass AECs) is included, the net cost of PDCs is the same as Oil at $ .80 a gallon and LP at $ .57 a gallon!! Download our PDC Cost Comparison Infosheet
PDCs are manufactured in and delivered from Froling Energy’s plant in Peterborough, NH