Generating Electricity from a Log Burner

After many years spent in academia and at the cutting edge of research I can hand on heart say there have only ever been a handful of times I have witnessed an idea or a thought that can truly be called revolutionary and game changing.’s invitation and visit to Xtralec was one such milestone.

An idea, a design drawing or even better in this instance a fully operational and functioning product prototype with the ability to change the way we live in the post industrial world and possessing the inherent capabilities to transform how the most impoverished and geographically isolated live their lives. The story doesn’t even end there  Xtralec have arguably through their diligence, hard work, tenacity and self-belief provided in part the answer to the major global environmental issues of the day as we in the industrialised world hastily retreat from macro to micro models of power generation.

We were met by Howard Pym and Steve Ashcroft the two very convivial senior directors of Xtralec and shown into their quite modest workshop in comparison to what was about to be unveiled and demonstrated.   We were presented with on first appearances -we all know what they say about books and covers- and for all intent and purposes looked like a conventional domestic log burner. The type of log burner you might find and is enjoyed in many conventional homes. The only difference being this log burner was set in a display of 40 ten watt lights with a bank of five stacked radiators on either side. Perhaps more telling of the apparent sorcery and high tech wizardry we were about to witness were a bank of computers and display screens set around the workshop all linked into a single piece of top end diagnostic and monitoring gadgetry installed to the right-hand side of the display stand.

I can only equate the entire experience as initially similar to being involved in a magic show but a magic show unlike any other.  We were invited to examine the display stand front, back, top, bottom and sides for any wires or other concealed trickery. We were even asked to thoroughly inspect the log burners integral log store which we understand will be available on the production models due out early summer next year obviously dependent upon which model you choose to furnish your home. What we were about to observe beggared belief and as a lay man rather than an expert as far as thermoelectric generators (TEGs) or Seebeck generators and high end electrical theory goes I can only describe what we witnessed as magical as the most primitive form of energy known to humankind fire was transformed into what is arguably the world’s greatest asset electricity.

Within a matter of minutes of the stove being lit the display lights began to flicker and twinkle and within ten or so minutes all forty lights were shining bright displaying their maximum luminosity. This was confirmed by the reading on the computer monitor indicating the stove was performing at 100% of its 1Kw generation capacity. The ten radiators soon enough reached there pre-set limit of 50 degrees Celsius with a five degree safety margin built in as not to exceed the legal maximum of 55 degrees Celsius. This was again confirmed and verified by the readings on the computer monitor, a hand held spot thermometer and the necessity of opening the doors and windows of the workshop in this unusually clement autumn weather we have been enjoying of late. I can personally vouch that there is very little or no loss of heat from the performance of the stove as I was very quickly forced to move my chair from in front of the radiant heat wave emanating directly from the stove.

For the more technically minded the electricity is generated by the TEG’s or Seebeck generators seated within the body of the stove. These apparently simple devices which have no moving parts are therefore incredibly robust and not prone to operational breakdown are able to convert the heat differential between the firebox of the stove and the unique patent applied for cooling system set within the skin of the stove to electricity.  As already alluded to it is not the absolute temperature of the stove but the heat differential between the stoves standard firebox and the positioning of the TEG’s in relation to the cooling system which not only produces electricity but produces it in a stable and harnessable  form with little or no voltage fluctuation.  The fundamental integrity of the stove’s construction is left intact and the stove will continue to meet the same CE regulatory ratings and DEFRA exemptions applied to a conventional wood burning stove. The Xtralec wood burning stove will also be eligible for the Domestic RHI grant and feed in tariff once in production.
As with all great inventions they are underpinned by quite simple ideas and concepts where the true genius is expressed is in their application and the nurturing of the idea or dream into a functioning reality. I know Howard and Steve and their Xtralec team of collaborators includes eminent electrical scientists specialising in thermoelectric generation, top class stove and production engineers and that their travels have taken them as far afield as China in search of the right materials, knowhow, and components. As Howard no stranger to the world of stoves and fuels said “I feel my whole life has led me to this point.  From the initial thoughts of providing a light, for myself, in a hut whilst I was engaged in establishing a school for local children in rural Africa from the energy of a  t-light and my entire professional working life have culminated here and are crystallised  in this stove.“


It would be a grave disservice on the part of to the Xtralec team and to the hours, money, dedication and sheer tenacity Howard and Steve have invested in to turning their dream of producing electricity from a log burning stove into a reality if we left you with the illusion that it was as effortless as waving a magic wand. But on the other hand it is a real indication of the mark of the character and a credit to the genuine modesty of the two men that stand behind what will be a world beater as its wider applications and social, economic and environmental implications are realised for the many who stand to benefit the most from a genuinely life changing innovative technology.

I will now leave you in the very capable hands of Howard Pym and Steve Ashcroft who have kindly agreed to share the Xtralec story and journey with Designer Fireplaces Newsletter readers as they move from prototype, to production and distribution to bring the Xtralec stove to market early next summer….Watch this Space

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