THE GREEN FILES
By Sonia Green-Brown, PE
Issue 229- Waste to Energy
I recall watching a cartoon with my daughter a few years ago, based on this environmentally conscious group of children, their teacher and a magic flying bus. When this group needed to fuel up they simply grabbed armloads of trash and shoved them down what was presumed to be the gas tank. This show, though fantasy offered a simplification of a real solution to energy, that of converting some form of waste to fuel. The conversion of waste cooking oil to biodiesel is actually in practice on the islands of Eleuthera and New Providence today. In this instance the used cooking oil goes through a conversion process before being able to be used in cars, so please don’t pour Crisco down your gas tank and say I told you so. For a country though, that has a waste problem and a fuel problem it’s time for us to seriously consider how we might use available technology to solve both these problems.
For my part I would like to see us use a multi faceted approach. We should, I believe, get as much as possible out of the recycling of used cooking oil into biodiesel and also look at maximizing the scrap metal business. We have a group of persons doing this now and more could be done to provide regulation and support to them. Further, we could formally introduce the sorting of trash at the New Providence landfill site to remove valuable scrap metals and other items that can be sold on. We may not want to admit this, but there already is a sector of the population that scavenges through the dump site on a regular basis looking for items they can reuse or sell. Formalizing this process may be a way of providing employment and a level of dignity to this group.
As an example of how to take this a step further, we can look at Spartanburg, South Carolina for inspiration. For 10 years now BMW’s assembly plant has been capturing methane via a 9-1/2 mile pipeline from a nearby landfill and was looking to upgrade from a 4 turbine system to a more efficient two turbine system in 2009. It is reported that BMW saved $5 million on average annually since 2002. The plant which cogenerates electricity and hot water used in the assembly process was set to be upgraded such that the combination of electricity and hot water production provided 60% of the energy needed for the plant.
The Allington Quarry Waste Management Facility found in the United Kingdom and operational since 2008, is one of 13 waste to energy plants in the UK. It generates sufficient power for 120,000 homes using 65,000 tonnes a year of pre-sorted material collected from homes and businesses. At maximum capacity it can produce 43 megawatts of power. Recyclable material is sorted out and sent to recycle centers and the remaining trash is incinerated to generate electricity.
There are many more examples of success we can look at around the world. For The Bahamas we need to see the passage of legislation to allow private enterprise to set up waste to energy plants for the provision of electricity and the government’s role should be to ensure that good environmental practices are adhered to along with constant monitoring of plant emissions to ensure these meet strict requirements. These and other bold initiatives will help us begin to provide a myriad of sources of energy for years to come.
We would like to hear how this article has helped you. Send questions or comments to sbrown@graphitebahamas.com.
Sonia Brown is Principal of Graphite Engineering Ltd and is a registered Professional Engineer.
