Carnegie Mellon University
June 18, 2020

Electricity for All

By Dan Carroll

Dan Carroll
  • College of Engineering

Organizations like the World Bank imply that equality is an important aspect of their goals for expanding electricity access in developing countries. Yet few studies have actually addressed how to ensure equality in developing areas like sub-Saharan Africa, and many have even used methods that further inequality. Destenie Nock, assistant professor of engineering and public policy in CMU's College of Engineering has led the first study to "explicitly integrate a stakeholder's preference towards equality into an electricity planning problem."

Most research to date has taken a least-cost perspective when considering economic criteria, meaning they estimate future electricity demand and attempt to minimize the cost necessary to meet it. Since it is difficult to project the future electricity demands of those who currently have little or none, this estimation disproportionately favors urban areas — which creates the appearance of higher demand, which further perpetuates a cycle of unequal investment. Nock chose instead to use an opportunity-focused model that recognizes that people's demand for electricity often rises as supply grows and new opportunities emerge. This model also accounts for load shedding, often in the form of planned blackouts, that often occurs in developing countries.

"I am interested in incorporating more voices and objectives into electricity planning," said Nock. "Traditional models are focused on developing low cost systems, which is very important, but there are many more objectives — like equity, climate mitigation and justice — that should be incorporated into energy systems planning."

Nock and her co-authors noted that the most effective technology for supplying a region differs, depending on its current energy infrastructure. Though connection to a centralized electrical grid is often preferred, research shows that decentralized systems are more economically viable in regions without existing power system infrastructure.

Nock's team created a methodology for finding the optimal expansion of a power system that maximizes social benefit within a constrained budget. They chose the West African country of Liberia as an example study. Years of civil war have caused extensive damage to the country's energy infrastructure, and the only major power generation facilities remaining after the conflict's end are centered around the urban capital of Monrovia.

Their calculations emphasized providing the greatest number of individuals access to electricity under different budget constraints, rather than simply meeting an assumed demand at the least cost. While the latter might lead to higher overall consumption, they found that countries that place a higher emphasis on equality can see a 72-87 percent increase in energy accessibility, depending on their budget. Greater investment in transmission infrastructure leads to higher electrification rates overall.

The researchers also found that while decentralized systems may be more economically viable in unsupplied regions, they can actually discourage equality, especially at low budgets due to scalability issues. They showed that investing in low-cost decentralized systems like solar discourages investment in transmission infrastructure, decreasing electricity access overall.

Four maps of Liberia. Map one shows 91 kilowatts per capita with a gini score of 0.85, map two shows 42 kilowatts per capita with a gini score of 0.18. Map three shows 320 kilowatts per capita with a gini score of 0.47 and map 4 shows 272 kilowats per capita with a gini score of 0.06

The researchers created four different scenarios of how electrical power could be expanded in the country of Liberia based on various equality preferences. A high Gini index indicates greater inequality in the income of wealth distribution of a nation’s residents.

Through their methodology, Nock and her team demonstrate that investment in an interconnected power system is key for equitable electrification planning in developing countries. Their opportunity-focused approach eliminates the urban bias of prior least-cost approaches and is widely applicable in countries with little to no electricity access like Malawi, Sierra Leone, Burundi and Burkina Faso, or in disaster-affected nations like Puerto Rico.

Nock's broader research interests revolve around systems modeling, the food-energy nexus and energy justice. She plans to continue adding new measures to improve the model and include a larger scope of stakeholder preferences.

"I am hoping to continue this research to incorporate other preferences and electricity planning goals, including CO2 emissions, and climate mitigation planning," said Nock. "There are many different preferences stakeholders have regarding electricity, equity, and sustainability goals, which I feel are not currently incorporated in energy optimization models."