Abstract:
Electricity supply in Nigeria is far below its demand with an all-time peak power generation of 5,420.30 MW as against estimated demand of over 30,000 MW. Bridging the electricity Demand-Supply gap in a sustainable manner requires the utilisation of renewable energy that supports both grid-tied and distributed technology. Concentrated Solar Power (CSP) technologies offer such solution. Literature is however limited on the feasibility and economic viability of CSP technologies in Northern Nigeria. More so, despite the vast direct normal irradiance endowment in Northern Nigeria and the high efficiencies of thermal energy storage associated with CSP, the technology is yet to be incorporated into the electricity generation mix in Nigeria. This study was therefore designed to conduct a techno-economic mapping of CSP technologies across widely selected locations in Northern Nigeria.
The Theory on Solar Radiation formed the framework. Data comprised an 18-year (2001-2018) meteorological records from the Nigerian Meteorological Agency and the European Union Photovoltaic Geographic Information System. A comparative analysis of ten locations in Northern Nigeria was conducted using the Angstrom-Page and Hargreaves-Samani equations in linear, quadratic, and cubic forms. The top five locations suitable for CSP deployment were identified through a weighted approach, and solar radiation models were developed for them. Typical Meteorological Year 3 (TMY3) data were subsequently developed from Finkelstein-Schafer statistics to simulate energy output and Levelised Cost of Electricity (LCOE) or break-even cost. This study also determined optimal concentrator, through comparative analysis of variants of Parabolic trough concentrator (PTC) model of CSP, and other system requirements using the System Advisor Model (SAM) Software.
Two locations (Maiadua 13°08'54"N, 8°13'41"E and Malam-Fatori13°40'59"N,13°19'59"E) were suitable for a 100 MW CSP plants, while the other three (Machina 13°08'11"N,10°02'57"E, Gada 13°46'32"N, 5°39'47"E and Zaria 11°11′N, 8°14'28"E) were found suitable for 50 MW CSP plants. The annual estimated energy outputs from the five locations were 341,702,879KWh, 323,484,204 kWh, 179,176,312 kWh, 170,673,093kWh and 155,710,024kWh, while the estimated LCOE of the proposed plants were US¢15.7/kWh, US¢15.8/kWh, US¢14.7/kWh, US¢15.4/kWh and US¢16.5/kWh for Maiadua, Malam-Fatori, Machina, Gada, and Zaria, respectively. Sites within latitudes 13°N and 14°N were suited for the deployment of CSP in the region. Furthermore, Sky Fuel Sky Trough 80-mm OD receiver was the preferred concentrator, Therminol VP-1 was the preferred heat transfer fluid, and HITEC Solar Salt the preferred thermal energy storage medium. The CSP plants could only be sited when and where the security situation permitted.
Five locations in Northern Nigeria can accommodate and efficiently deploy 50 MW to 100 MW CSP plants. Thus, a sustainable model of electricity generation capable of supporting industrial applications in an environmentally friendly manner has been formulated. Government should support CSP investments in Northern Nigeria through favourable power purchase agreements and feed-in-tariffs.
