Dr. Samuel Gyamfi, Mawufemo Modjinou, Sinisa Djordjevic
School of Engineering, University of Energy and Natural Resources (UENR), P. O. Box 214, Sunyani, Ghana. Email: email@example.com
The major global energy challenges are: a) securing a sufficient energy supply to meet growing demand, b) providing everybody with access to energy services, and c) curbing that energy’s contribution to climate change. In developing countries, access to affordable and reliable energy services is fundamental to reducing poverty and improving health, increasing productivity, enhancing competitiveness and promoting economic growth.
As Ghana is a developing country, the country’s electricity demand has long been relatively low, although demand has been rising in recent times due to increasing economic growth, urbanization and industrial activities. According to Ghana’s Energy Commission, electricity accounted for about 9% of the country’s 9.50 Mtoe total final energy consumption in 2007. Biomass and petroleum fuels accounted for 64% and 27% respectively of final energy consumption. About 65% of the country’s electricity is generated from a large hydropower station, with the remaining 35% provided mainly from an array of thermal power plants that operate on gas, diesel and light crude oil. The national access to electricity is currently about 71%, with the access of urban inhabitants at 78% and the rural population access rate of less than 30%. The government’s national electrification scheme policy objective is to electrify all communities with populations above 500 by the year 2020.
Ghana’s electricity sector is saddled with many supply challenges. The existing power plants are not able to attain full generation capacity due to fuel supply constraints, as well as the uncertainty of rainfall and water inflows into the hydroelectric power facilities. The rapid demand growth and periodic hydrological shocks leave the country increasingly reliant on expensive oil and gas-based generation power plants. However, the power tariffs are based on the costs of base-load hydropower, which means that more expensive oil-based generation plants operate at annual financial losses to the Volta River Authority (VRA). The low tariff regime, which does not allow for a full cost recovery, has slowed down capacity expansion. The recent power shortages have been attributed to the lack of capacity addition to meet the growing demand. It is estimated that Ghana will require a new capacity addition of about 200MW each year to catch up with increasing demand in the medium to long term.
The transmission and distribution infrastructure of the country has been extensive since the National Electrification Scheme was instituted in 1989, but has deteriorated since then, resulting in frequent interruptions to power supply, transmission bottlenecks, overloaded transformer sub-stations and high system losses. The losses in the transmission and distribution systems are estimated at 25%, while wastage in the end-use is estimated at about 30% . Rolling blackouts and severe restrictions on energy consumption are often employed by the main utility companies (VRA, GRIDCo, and ECG) to manage power supply constraints. It is clear that Ghana will have to improve its network infrastructure, as well as expanding and diversifying its installed capacity in order to improve supply reliability.
The three most important factors in selecting new energy resources that ensure supply security are that they must be renewable, locally available at reasonable costs, and environmentally friendly. The government energy policy objective aims at expanding generation assets by investing in renewable energy systems and energy efficiency measures.
Dr. Samuel Gyamfi and his colleagues at the Department of Energy and Environmental Engineering of the University of Energy and Resources have investigated the potential contribution of renewable energy resources to the improvement of the electricity supply security of the country. Their investigation also identifies barriers for utilizing these resources for electricity generation in the country, and reviews government policies and programs to promote utilization of renewable energy.
Their results show that Ghana has several renewable energy resources (RES) such as wind, solar PV, mini and small hydro, and modern biomass that can be exploited for electricity production. The installed capacity of hydropower, for instance, is small compared to the exploitable potential. The development of solar power has been limited to a few homes, usually in the form of solar home systems. Despite a good wind and biomass resource potential, the technologies to harness them for electricity production have so far not been demonstrated on a commercial scale in the country.
According to study, Ghana has approximately 413 km2 area with good-to-excellent wind resource (wind class 4 ̶ 6) which could supporta little over 2,000 MW of wind power development, and if moderate-to-excellent wind resources were included, that could go up to 5,640.
The country has an estimated additional hydropower potential of 2000 MW, of which 1200 MW is expected to be produced from proven large hydro sources, with the rest coming from small and medium-scale hydro sources.
Extremely large solar radiation resources are available in many parts of the country, especially in the northern regions where the electrification rate is very low. Considering that many parts of the country receive 5 ̶ 8 hours of sunshine per day at 1 kW/m2, the potential for using solar for electricity generation is very high.
While about 0.13% of the country’s electricity is generated from these resources (excluding large hydro), the study shows great potential for this to increase substantially over the next decade, due to government commitment and legal frameworks which are being put in place.
The barriers to renewable energy exploitation in Ghana include higher electricity costs compared to the non-renewably-sourced electricity; compatibility with existing transmission and distribution networks; the remoteness of resources from key electricity demand sectors; technological immaturity; institutional inexperience and the lack of skilled technical manpower to oversee renewable energy projects.
Ghana has a history of strategies and policies to promote renewable energy. However, looking at renewable energy installation status, one can say that these policies are yet to have significant impact on the renewables industry. The recently passed Renewable Energy Act to generate 10% of the country’s electricity from modern renewable energy sources by the year 2020 is expected to promote renewable energy business in the coming decade. It has created the enabling environment for the exploitation of the renewable energy resources in the country through the introduction of:
- feed-in-tariff (FIT) scheme which is made up of feed-in-tariff rates,
- mandatory purchase of electricity generated from renewable sources,
- free access to the distribution and transmission systems, and
- creation of the Renewable Energy Fund dedicated to the promotion development of the renewable energy sub-sector in Ghana.
The other commitments from the government can be seen in the establishment of the University of Energy and Natural Resources in 2011 to train people in Renewable Energy Engineering and other energy related skills. The KNUST has also introduced programs in renewable energy technology and has established an Energy Center to provide training, research and advisory services to public and private actors in energy technology, policy and management.
The University of Energy and Natural Resources students and staff have for example successfully designed and built biogas plant that supplies the university’s Cafeteria with biogas for cooking. The university is currently planning to build Solar Modules Assembling Plant targeting the Ghanaian solar energy market.
The full text of the study “Improving electricity supply security in Ghana—The potential of renewable energy’ involved University of Energy and Natural Resources and Murdoch University (Australia) can be found in the link http://dx.doi.org/10.1016/j.rser.2014.11.102