Power and Energy Production in the World

Lessons

Senior 6 · Geography

Power and Energy Production in the World

4 lessons

Lesson 4 of 4

Energy and Sustainable Development: Problems and Solutions

25 min

The energy gap

In 2015 the United Nations adopted Sustainable Development Goal 7: ensure access to affordable, reliable, sustainable and modern energy for all by 2030. Figure 1 shows how far the world still had to go a decade later.

Figure 1: Access to electricity and to clean cooking, world and sub-Saharan Africa. Data: World Bank.

Analyse the chart. Outside sub-Saharan Africa almost everyone now has electricity, but only about half of sub-Saharan Africa's people do, and fewer than one in four cook with clean fuels such as gas, electricity or biogas. The rest burn wood, charcoal, crop waste or dung, usually indoors. Rwanda has moved fast: Rwanda Energy Group reports that 85.4% of households had electricity by the end of 2025, counting both grid connections and off-grid solar systems. Clean cooking is the harder gap: in the 2022 census, 76% of Rwandan households still cooked mainly with firewood (NISR).

Definition

Sustainable development: development that meets the needs of the present without compromising the ability of future generations to meet their own needs (Brundtland Report, 1987). It has three pillars: economic, social and environmental.

Energy poverty: lack of access to modern energy services: electricity and clean cooking.

Clean cooking: cooking with fuels and stoves that do not pollute the home: electricity, liquefied petroleum gas (LPG), natural gas, biogas or solar, and some efficient stoves.

Energy mix: the combination of sources a country uses. A diversified mix depends on no single source.

Energy efficiency: getting the same service (light, heat, transport) from less energy.

Greenhouse gas: a gas such as carbon dioxide (CO₂) or methane that traps heat in the atmosphere.

Why energy matters for sustainable development

Pillar	How energy helps	Example
Economic	Powers factories, mines, irrigation pumps, offices and digital services; creates jobs; attracts investors; cuts the cost of imports when produced at home	Factories in the Kigali Special Economic Zone need reliable power; the 3.3 MW Nasho solar plant pumps water to irrigate farms in Kirehe District
Social	Lights homes for study; runs health centres, vaccine fridges and hospital equipment; pumps clean water; saves time spent collecting firewood, mostly by women and girls	Solar kits in remote villages; electricity in rural health centres and schools
Environmental	Clean fuels cut deforestation, soil erosion and indoor smoke; low-carbon power slows climate change	LPG and biogas replacing charcoal; hydro and solar replacing diesel

Problems of energy production

Climate change. Burning fossil fuels releases CO₂; the energy sector produces around three quarters of the world's greenhouse gas emissions (IEA, Net Zero by 2050, 2021).
Pollution and accidents. Smog and acid rain from coal; oil spills in the Niger Delta and the Gulf of Mexico; radioactive releases at Chernobyl (1986) and Fukushima (2011).
Deforestation. Cutting wood for fuel and charcoal faster than it regrows strips hillsides, which erode and slide in heavy rain.
Displacement and lost land. Reservoirs drown villages, farms and wildlife habitats, as at Kariba.
High cost and debt. Power projects need huge capital; poor countries borrow, and tariffs may be too high for poor households.
Unreliable supply. Droughts cut hydropower; solar and wind are intermittent; old lines lose energy and break down.
Dependence on imports. Landlocked countries such as Rwanda import all their petroleum through long corridors, so world price rises and border delays hit them hard.
Conflict over shared resources. Egypt and Sudan long opposed the filling of the Grand Ethiopian Renaissance Dam on the Blue Nile, fearing less water downstream; Ethiopia officially inaugurated the dam in September 2025 without a binding agreement.

Possible solutions

Problem	Possible solutions
Emissions and climate change	Shift to renewables and other low-carbon sources; international agreements such as the Paris Agreement (2015); capture of carbon from power stations
Deforestation for fuel	Improved cookstoves that use less wood; biogas; LPG and electric cooking; woodlots and agroforestry
Unreliable supply	A diversified mix (hydro, methane, peat, solar and imports in Rwanda's case); storage in batteries or pumped-storage reservoirs; regional power pools and interconnectors
Lack of access in remote areas	Off-grid solar kits and mini-grids; subsidies for poor households; pay-as-you-go payment by mobile money
High cost and import dependence	Develop local resources; attract private investment through clear contracts; buy power from neighbours through shared plants
Waste of energy	Efficient bulbs, motors and buildings; cutting transmission losses; time-of-use tariffs
Social and environmental damage	Environmental impact assessment before building; fair compensation and resettlement; sharing benefits with local communities
Conflict over shared rivers	Basin-wide agreements and joint institutions, such as the Nile Basin Initiative

Worked example 1: what efficiency is worth

Problem. A household replaces five 60 W filament bulbs with 9 W LED bulbs giving the same light. The lights are on for 5 hours each evening. (a) How much energy does it save in a year? (b) At an illustrative price of 250 Frw per kWh, how much money is saved? (c) If 100 000 households did the same, by how much would the evening peak demand fall?

Solution.

\text{(a) Power saved} = 5 \times (60 - 9) = 255\,\text{W}

255\,\text{W} \times 5\,\text{h} \times 365 = 465\,375\,\text{Wh} \approx 465\,\text{kWh per year}

\text{(b) } 465 \times 250 \approx 116\,000\,\text{Frw per year}

\text{(c) } 100\,000 \times 255\,\text{W} = 25.5 \times 10^{6}\,\text{W} = 25.5\,\text{MW}

That is almost the capacity of the 26 MW KivuWatt methane plant. Saving energy can be as useful as building a new power station, and far cheaper.

Worked example 2: emissions avoided

Problem. A country replaces 100 GWh a year of coal-fired electricity with solar power. Taking an illustrative emission factor of 0.95 kg of CO₂ per kWh for coal and treating solar power as zero-emission while running, how many tonnes of CO₂ are avoided each year?

Solution. Convert GWh to kWh: $100\,\text{GWh} = 100 \times 10^{6}\,\text{kWh} = 1.0 \times 10^{8}\,\text{kWh}$ .

1.0 \times 10^{8} \times 0.95 = 9.5 \times 10^{7}\,\text{kg} = 95\,000\,\text{tonnes of CO}_2

Evaluation: the saving is real, but solar panels still cause some emissions when they are made and transported, and the country needs storage or other plants for the night, so the true saving is a little smaller.

Warning

Common mistake. Treating "more energy" and "sustainable development" as the same thing. A coal plant that brings power to a city but poisons its air and raises emissions is development, but not sustainable development. In an evaluation, test each energy project against all three pillars: is it affordable, does it reach the poor, and does it protect the environment?

Tip

Exam technique. Pair every problem with a matching solution and a real place, for example: deforestation for charcoal → improved stoves and LPG → Rwanda; drought cuts hydropower → diversified mix and regional imports → Zambia and Zimbabwe at Kariba. Paired answers score better than two separate lists.

TED-Ed: "Why aren't we only using solar power?" by Alexandros George Charalambides. Watch for the reasons the video gives: cost, storage and the variation of sunlight with place and time, and link each to a solution in the table above.

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Practice

State the aim of Sustainable Development Goal 7.
Using Figure 1, by how many percentage points did access to clean cooking in sub-Saharan Africa lag behind the world average?
Explain two ways in which energy supports social development.
Describe three environmental problems caused by energy production, each with a named example.
A school replaces twenty 40 W tubes with 18 W LED tubes, used 6 hours a day for 200 school days. Calculate the energy saved in kWh.
Suggest how a landlocked country can reduce its dependence on imported petroleum.
"Off-grid solar is a better way than the national grid to bring electricity to rural Africa." Evaluate this view.

Show answersHide answers

To ensure access to affordable, reliable, sustainable and modern energy for all by 2030.
74.4 − 22.8 = 51.6 percentage points.
For example: electric light lets children study after dark; electricity runs health centres and vaccine fridges; clean fuels save women and girls hours spent gathering firewood and cut smoke-related illness.
For example: CO₂ emissions and climate change from coal (China, South Africa); oil spills (Gulf of Mexico 2010, the Niger Delta); deforestation and erosion from fuelwood and charcoal (East Africa); flooding of land by reservoirs (Kariba).
20 × (40 − 18) = 440 W; 440 W × 6 h × 200 = 528 000 Wh = 528 kWh.
Develop local energy (hydro, solar, methane or biogas); electrify transport and cooking with locally produced power; improve efficiency; store fuel strategically; diversify import routes and suppliers.
For: quick and cheap to install in scattered homes; no long lines; pay-as-you-go by mobile money; it already reaches many Rwandan households. Against: kits give little power, not enough for mills, workshops or irrigation pumps; batteries wear out and need recycling; the grid gives cheaper power per kWh where people live close together. A balanced judgement: off-grid solar is best for remote, scattered homes and as a first step, while the grid and mini-grids are needed for productive uses and towns.

Summary

Energy drives all three pillars of sustainable development, but in 2024 only about 55% of people in sub-Saharan Africa had electricity, and in 2023 fewer than a quarter cooked cleanly (World Bank).
Problems include emissions, pollution and accidents, deforestation, displacement, high costs, unreliable supply, import dependence and disputes over shared rivers.
Solutions pair with problems: renewables and efficiency, clean cooking, diversified mixes and regional pools, off-grid solar, impact assessments and basin agreements.

1The energy gap

2Why energy matters for sustainable development

3Problems of energy production

4Possible solutions

The energy gap

Why energy matters for sustainable development

Problems of energy production

Possible solutions