How renewables and fossil fuels can work together to power the future
From chicken manure to kites, there are many innovative ways to create energy rather than traditional fossil fuels such as oil and gas.
But despite the very real need to reduce carbon emissions in order to protect the environment, the era of fossil fuels - and natural gas in particular – is far from over.
A recent McKinsey report predicts that fossil fuels will continue to dominate energy use through to 2050. But clean technologies - like wind and solar – will also grow four-to-five times faster than other power sources over the same period.
This means that, by the middle of this century, power generation is set to look very different to today. During the transition period, traditional fossil fuels and new renewable technologies will work in harmony, forming a unique interplay.
Much of the answer can be found in new technologies that allow fossil fuels and renewables to work in tandem, meeting increased demand at the same time as reducing emissions.
Fuelling the future
Power-to-gas technologies are a good example of this complementary partnership in action. There is often surplus capacity in the power grid especially on windy days, but this excess wind power can be harnessed to power electrolysis. This in turn is used to divide water molecules into separate hydrogen and oxygen elements. And once a ready supply of hydrogen is available, it can be fed into gas-fired power plants to help lower their carbon dioxide emissions.
Companies like Mitsubishi Hitachi Power Systems (MHPS) are exploring ways of using hydrogen in natural gas turbines for power generation. The company recently conducted successful tests using a stable blend of 30% hydrogen and natural gas to drive large-scale gas turbines. The tests reduced CO2 emissions by 10% and represent a positive first step towards realizing future hydrogen-only combustion, which would cut emissions to zero.
There are also many ongoing innovations within the wind power generation business itself. Shell, for example, has taken the idea of wind power to new heights by investing in a prototype kite that hovers 300 meters or so above ground level.
The kite is tethered to land and kept aloft by prevailing winds which generate movement and produce electricity. Once the concept is fully developed, Shell’s offshore oil & gas presence has the potential to carry the idea out to sea where winds are strongest.
This new method of capturing the wind’s energy could be ideal to feed into increased demand for electrolysis as the use of hydrogen also increases.
Re-using and recycling
Capturing residual heat from existing power plants or other industrial processes is another way of making the energy supply chain renewable, making efficient use of existing resources.
Waste-to-energy technology is one example of this. MHI Group company Turboden has invested in Organic Rankine Cycle (ORC) system turbines in order to capture residual heat and use that heat to produce power.
For example, ORC turbines installed in a chicken farm in Turkey generate electricity from combusting the manure of 14 million birds. The process removes the unwanted biowaste – which is plentiful and in continual supply - and generates electricity to sell on to power companies.
Such technologies can also be fuelled from natural sources like geothermal energy, where steam is harnessed from thermal springs to drive turbogenerators. The end product, once again is power to feed into the grid.
And even in plants which continue to rely almost exclusively on fossil fuels, there are ways to make them less harmful to the environment.
Technologies like carbon capture and storage can reduce or remove the harmful exhaust emissions.
The Petra Nova project in Texas is the world’s largest carbon capture facility operating at an existing coal-fired plant. More than 90% of carbon dioxide emissions are captured from the site’s 240MW slipstream of flue gas, which would otherwise reach the atmosphere.
Once captured, carbon can be securely stored below ground, used in industrial processes such as manufacturing concrete, and even used in enhanced oil recovery techniques that push hard-to-reach oil to the surface.
Such innovations will continue to transform the power generation sector as well as the oil and gas industry.
And some of the most effective solutions will see renewable energy sources and fossil fuels working together, ensuring a supply for tomorrow’s power needs while respecting the environment.