The UN Millennium Project
On September 8, 2000, 189 member states of the United Nations signed the Millennium Declaration Resolution to form a partnership to achieve broad-based goals of reduction in world poverty, environmental degradation, and infectious diseases by 2015. These targets, called the Millennium Development Goals (MDGs), serve as the objectives for addressing "extreme poverty in its many dimensions--income poverty, hunger, disease, lack of adequate shelter, and exclusion-while promoting gender equality, education, and environmental sustainability." Commissioned by the UN Secretary General, the Millennium Project strives to provide strategic roadmap to achieve each MDG through a combination of political, financial, and technological means.
In a 2005 executive report on the state of the Millennium Development Goals (MDGs) of the United Nations Development Program, Jeffrey Sachs, director of the Millennium Project states that there is an "urgent need to improve access to energy services as essential inputs for meeting each MDG." This need is especially critical in rural areas of developing countries where access to energy services such as electricity or gas, is either scarce and costly, or completely unavailable . The implementation of reliable, cheap and sustainable energy service solutions will allow the rural poor in developing countries to improve their quality of life through use of electricity and electrical applications.
The Lister 6/1 CS Engine
To address the needs of rural, developing communities, the Modi MVP Group at Columbia has identified the Lister 6/1 CS diesel engine running off Jatropha seed fuel oil as a candidate energy service solution for Sub-Saharan Africa and India. The package addresses the needs of these communities by providing a robust engine and generator system, while also addressing the issue of sustainability and environmental preservation. The Lister 6/1 CS itself is a one cylinder, four-stroke, low-RPM diesel engine designed in 1930 and produced by Lister Co. of Gloucestershire. Though no longer produced by Lister Co. (now Lister-Petter Diesel), various Indian manufacturers continue to produce very low-cost clones of the Lister design.
The Lister 6/1, by virtue of it’s robustness and simplicity, can be easily modified to utilize Straight Vegetable Oil (SVO) fuels, such as Jatropha. By running the engine off Jatropha seed oil, fossil fuels are avoided and carbon is absorbed from the atmosphere by the Jatropha plants grown to yield the seed oil. Therefore, the overall contribution of CO2 to the atmosphere by the Jatropha-fueled engine is significantly less than engines powered by fossil fuel . Moreover, the Jatropha plant grows very well in semi-arid conditions and is non-edible, meaning that producing fuel from Jatropha seed does not compete with edible food production (i.e. corn-based ethanol, etc.).
The Lister type 6/1 CS engine has been identified as an ideal energy service solution for rural, developing communities based on it’s robust construction, simple design, ease of maintenance and wide availability. Used mainly in fixed-load applications such as pumping or agro-processing, the Lister has the potential to provide electricity and general energy services to emerging communities across Africa and the Indian Subcontinent. However, the one shortcoming that makes this difficult is the Lister enginefs poor load following characteristics. Designed as a constant RPM engine, the Lister does not handle varying loads well, as is required by a constantly varying electricity grid. To this end, a RPM-feedback control system will be designed to achieve constant RPM over varying loads. In this way, the Lister can be coupled to an AC generator head and thereby generate constant AC current without the need for an expensive inverter, increasing the usability of the Lister platform while lowering cost for developing communities.
Applications of Lister Engines: Fixed vs. Variable Loading
Applications of the Lister 6/1 CS in Africa and the Indian subcontinent have thus far been limited to very basic, fixed load scenarios where the engines must sustain a constant load and speed. These mainly include irrigation and pumping, agro-processing and basic light industrial applications, which the Lister performs excellently. The glaring omission from the list is electricity generation, which many villages so desperately need.
The Lister 6/1, because of it’s extreme simplicity, is often considered to be a rough service engine that sacrifices control and precision for robustness and a cheap price. As a result, the load following characteristics of the engine are poor (see graph below), meaning that when the load on the engine varies, the engine will either be overloaded and die or be under-loaded and go out of control. To be suited for use in an electrical grid, the engine itself must be able to modulate between varying loading scenarios of the components within the network. For example, if a light bulb, microwave and clothes dryer were connected to the grid, the loading when only the light bulb was on would be very different from the load when all the appliances were in use.
Design Objectives
The main objective of the design is to create a control system to actively control the RPM of the Lister engine and increase the versatility of the engine and its ability to operate under varying load. Key factors that affected the design include cost, ease of installation, ease of operation, and durability. Please see the design section for more details.
