Senior energy experts from Wärtsilä present the latest results of an in-depth study which models the most cost-effective and reliable energy mix that can be built each year in Nigeria
To identify the most cost-effective and sustainable power generation strategies for Nigeria, Wärtsilä’s most recent 2022 to 2040 Analysis of Nigeria’s National Power System has used the advanced Plexos modelling tool, which quantifies system level benefits of different technologies in the Nigerian power system. The model shows that the country requires more aggressive capacity additions than the current situations, referred as business-as-usual scenario, if it is to achieve the country’s stated 30-30-30 vision.
But looking beyond 2030, and by mapping the country’s solar and wind potential for renewable energy, together with transmission data from five major regions, the model shows that an advanced 30-30-30 scenario can be envisaged which would generate additional power and significant cost savings.
This advanced scenario recommends the installation of 45GW of low-cost renewables in the North and West of the country by 2040, while concentrating 43GW of gas-fired internal combustion engine (ICE) power plants in the southern regions with access to low-cost locally sourced gas. Strengthening the transmission capacity between North and South will greatly benefit the central regions as well.
As more capacity is added to the system, the cost of electricity is predicted to fall drastically within the first years, as locally sourced gas fuels more cost-efficient gas power generation to overtake expensive diesel. With the advanced scenario, cumulative saving to 2040 of up to US$430bn can be achieved when compared to the business-as-usual scenario.
A flexible solution to meet the needs of the Nigerian market
For Wärtsilä, the choice of power generation technology is as important as the choice of fuel. In a system that maximises the use of low-cost renewables, being able to rely on flexible power technologies becomes paramount.
In this context, ICE power plants become the technology of choice because they are flexible by design. They have a high operating efficiency, even at partial load, and are made to cope with regular start and stops. On the other hand, combined cycle gas turbines (CCGT) lack the flexibility to match the fluctuations in electricity demand. They rely on a consistent and pressurised gas supply and are most efficient when operated close to full capacity. They are not suited to offset the intermittent supply of renewables.
Detailed technology comparison between CCGT and ICE power plants show that for an equivalent 350MW plant running 8,000 hours per year, Wärtsilä’s solution saves between US$11-17mn per year compared to CCGT solution, thanks to its better performance in hot climates, better part-load efficiency and lower investment cost.
But there is more. Flexible ICE power plants offer several other advantages relevant in Nigeria. Thanks to their modular design, ICE power projects are easy to construct, fully scalable and can be deployed in phases. They can be ramped-up or down quickly to adjust to demand, and also provide a great hedge against fuel supply risk, as its engines can be operated on natural gas, Diesel, HFO or biofuels. What is more, they require little water to operate: their water consumption is less than 1% compared to the CCGT technology.
Today, Nigeria’s electricity system faces a perfect storm. Small, inefficient, expensive, and polluting diesel generators are widely used to compensate for weaknesses in the country’s grid capacity. Despite recent improvements, the gas supply system is not fully stable, which places additional strain on country’s still fragile electricity network.
Wärtsilä is convinced that building flexibility into the system by investing in gas engine power plants can provide a stable and reliable long-term solution to Nigeria’s energy challenges.