Energy from waste

David Scheeres David.Scheeres@aspen-waite.co.uk

Aspen Waite Sustainable Energy Ltd (AWSE) was incorporated on November 6th 2020 to make a profit from the development and production of an innovative Anaerobic Digestion system.

Anaerobic digestion is a process through which bacteria break down organic matter—such as animal manure, wastewater biosolids, and food wastes—in the absence of oxygen. Anaerobic digestion for biogas production takes place in a sealed vessel called a reactor, which is designed and constructed in various shapes and sizes specific to the site and feedstock conditions. These reactors contain complex microbial communities that break down (or digest) the waste and produce resultant biogas and digestate (the solid and liquid material end-products of the AD process) which is discharged from the digester.

The illustration on the right shows how this works.

Why would a firm of accountants involve themselves in Anaerobic Digestion?

The road to Aspen Waite Sustainable Energy began 15 years ago at a Recycling and Waste Management exhibition at the NEC. An enthusiastic young graduate, Waqas Ahmed explained his vision to me for small portable digestion plants and was seeking technical assistance on heating and the recycling of plastics, two fields I am involved in. Over the years Waqas reappeared many times requesting technical and business advice and on some occasions, to commiserate with him regarding problems with nonperforming investors. It is said that invention is 5% inspiration and 95% perspiration and in Waqas’ case this has proved to be true.

Waqas’ idea was to develop a portable digestion system which would have the advantage of not requiring solid foundations that a fixed plant would require. Planning permission is required for static AD plants and is often contentious and can take several years but a modular system does not need planning and as a consequence can be deployed where needed. To make them economically viable, large scale digestion plants require a large throughput of waste and the cost of transporting waste can be significant. There is a sensitive balance between cost of feedstock and value of the digestate. In respect of the Aspen Waite system, the plant is small scale so it is taken to the point of generation of waste and scaled to suit. I have long advocated dealing with recycling problems at source as transportation is expensive and not sustainable.

In 2020 a client explained to me that they had potential pollution issues with a leachate at a recycling plant and that there was a potential of a closure order from National Resources Wales, the Welsh equivalent of the Environment Agency.

Around 5000 litres of biological leachate was collected each day from a sump and spread on farm land. In the event of heavy rain the leachate was diverted into a large lagoon to employ reed bed filtration. NRW was dissatisfied with the reed bed option as it was considered it should be much larger and could overspill into a river during bad weather. The option for our client was to extend the reed bed lagoon which would seriously impinge on the space at a huge cost or give up recycling the waste stream from their customer, a Local Authority. The particular waste stream; nappy waste, was a very small part of the Local Authority contract but the contract was based on processing everything so cessation of that waste stream would have jeopardised the whole contract.

Pending legislation to be introduced in March 2022 will seriously restrict the spreading of silage on the land in Wales also compounded the problem for our client.

I suggested to the client that they could consider small scale digestion which would allow clean fluid to be discharged or used for washing vehicles with the additional potential of creating a saleable product – organic fertilizer.

Our client liked the idea, I spoke to Paul Waite and with his agreement contacted Waqas and Aspen Waite Sustainable Energy was created after a rapid business risk evaluation with the ambition of developing a pilot plant within 12 months to resolve our clients problem and then sell the technology to them and to others.

This gave Waqas the opportunity to scale up his technology and prove it with a pilot plant with a willing operator and Aspen Waite the opportunity to resolve a problem for an important client. A win-win scenario for all parties.

As a result of Waqas’ business development work, the Ministry of Defence have expressed significant interest to the extent that they wish to showcase the equipment at their Salisbury technology centre and run a trial.

In addition to defence the MOD also involves itself with assisting NGO’s (Non Government Organisations) such as Oxfam with post disaster humanitarian aid. Following natural or man made disasters there is always a requirement for clean water but providing sanitation is difficult resulting in contagious disease. The long term objective of AWSE is to sell the equipment to NGO’s for rapid deployment where needed. The digesters can provide sanitation and also energy from the methane gas produced. Energy costs are low as the main reaction is biological and the plants energy requirements can be met from solar panels allowing deployment in remote areas away from the Electricity Grid. The Aspen Waite digester is patents pending and has a unique heating circuit that accelerates microbacteriological growth to assist in the efficacy of the digestion.

There is a world wide reliance on chemical fertilizer for agriculture but a genuine desire to use organic fertilizers which are in short supply. Miniature digesters, placed where they are needed, such as in hotels, schools, farms and even sports and music festivals will reduce pollution, reduce traffic to and from sites and create a valuable saleable product that will assist the food growing chain.

Aspen Waite is particularly active in providing Corporation Tax Relief to the recycling and agricultural sectors so understands requirements and has an existing customer portfolio for the technology.

There is no doubt that the accounting profession is facing a radical restructuring as a result of digitalisation and inexpensive software packages such as Xero, Sage and Quickbooks will result in large scale reduction of the sector so diversification will provide opportunity and security for those that have agility and can deploy their skills elsewhere. Aspen Waite is such a company. The pilot plant is currently being commissioned and will be operational virtually one year to the date of the incorporation of Aspen Waite Sustainable Energy Limited.

AWSE Digester tanks with Solar Panels replacing reed bed lagoon.