Energy boost

On 24 February 2022, while we watched in shock as Russia invaded Ukraine, we may not have expected the skyrocketing fossil fuel prices that followed. That day, the price of natural gas rose by more than half in Europe. Crude oil prices rose above $100 per barrel for the first time since 2014.

The resulting energy price crisis comes with a need to change our energy strategy to prevent further environmental problems. The solution to both could be the same: renewable green energy, harvested from the wind, sun, water and earth – and even ‘green gas’ sourced from farm, food and landfill waste. Although current high prices are hard for many, they might push us towards a cheaper, cleaner, less problematic energy supply.

Fossil fuels come from the fossilised remains of plants and animals that died millions of years ago. Many of us heat our homes and cook our food using natural gas. This is a mixture of small carbon-based molecules, mostly methane, with smaller amounts of other gases, the most common being ethane, propane and butane. We rely on natural gas so much because its cost per unit of energy is just a quarter of that of the electricity we use. That is still true even with recent gas price increases.

Meanwhile, most vehicles still run on products found in crude oil. Crude oil is a much more complex mixture of hydrocarbons than natural gas, potentially containing thousands of different compounds. Chemical companies use fractional distillation to separate crude oil into smaller, more useful parts. The process separates fractions based on their different molecular weights and boiling points. Large molecules stay at the bottom of the fractionating column where it is hottest, going into products like heavy fuel oil. Moving upwards, fractions move from diesel, to kerosene, to petrol, each containing progressively smaller molecules with lower boiling points.

Some power plants use heavy fuel oil to produce electricity. Burning the molecules releases the energy they have held for millions of years. Burning diesel, kerosene and petrol powers vehicles by releasing energy in the same way.

From crisis to opportunity

However, burning fossil fuels also produces water vapour and carbon dioxide. Carbon dioxide is a greenhouse gas that acts as an insulating blanket in the Earth’s atmosphere. It retains energy that the Earth has absorbed from the Sun and then emitted again as infrared radiation. This warms the planet and is leading to dangerous climate change.

It isn’t just international war that’s to blame though. Problems had already been mounting in the UK for months. ‘The energy crisis in September 2021 was caused by a perfect storm in the final quarter of last year,’ Doug says. The winter was very cold, he notes, with little wind to generate electricity via turbines. Meanwhile, economies were consuming more electricity to try to recover from the pandemic. In addition, the UK government had closed its large gas storage facility. Previously this provided the option to buy more gas when prices were lower and use it when they increased. These factors all increase the pressure to develop alternatives.

On 7 June 2017, for the first time ever, the UK generated more electricity from renewable sources than fossil fuels

Creating renewable energy infrastructure only leads to small amounts of greenhouse gas emissions. They then generate many times more electricity than is used in their manufacture without any emissions, with a minimal contribution to the greenhouse effect. Recognition of the climate change threat has seen countries increasingly adopt such clean energy sources. For example, on 7 June 2017, for the first time ever, the UK generated more electricity from renewable sources than fossil fuels.

Realistic solutions

Conventional power plants and four of the five leading renewable energy options all rely on turning turbines to produce electricity. Burning fossil fuels heats water or steam, which drives turbines. Generators can do the same by burning biomass, plants that have recently pulled carbon dioxide from the air through photosynthesis. Geothermal energy heats the water or steam needed for the turbines using heat from beneath the Earth’s surface. Wind and hydroelectric power both directly harness renewable kinetic energy from the environment to turn turbines. Some forms of solar power also heat water to drive turbines, but more commonly they use silicon photovoltaic (PV) panels to directly convert sunlight to electricity.

The greenest energy in the world is the stuff you don’t use. We waste a terrifying amount as 21st-century consumers

It’s still more expensive to cook and heat homes with electricity than gas, too. That’s why Doug and his colleagues at Green Energy UK produce methane from biological sources. Microbes turn farm, food and landfill waste into ‘green gas’ in closed containers called digesters, without air. For this reason, the process is sometimes called anaerobic digestion. Green Energy UK puts the gas into the same national grid that fossil-based natural gas flows through. While not much demand can be met using green gas, it is cleaner and less problematic than buying from countries like Russia.

Such renewable energy technologies could solve many of the current energy problems, yet few of us are involved in putting them in place. If that feels frustrating, there are some things we can each do to make a difference. For example, we can change our behaviour and the way we use energy.

‘The greenest energy in the world is the stuff you don’t use,’ agrees Doug. ‘We waste a terrifying amount as 21st-century consumers.’