Driving power sector emissions down to zero is essential to achieve a net-zero economy. While creating a power system based solely on renewable power is technically possible, it would likely be excessively expensive because of the need to overbuild power capacity. Building a portfolio of flexible baseload, energy storage and grid technologies to assist variable renewable power will therefore be essential in creating a low-cost net-zero power system.
- Nuclear power is already a reliable and zero-carbon source of power but concerns around its cost and safety have caused the industry to stagnate. A new class of fission reactors hopes to cut costs by redesigning systems so that expensive elements of traditional plants, like huge concrete containment units, are no longer needed. Simultaneously, private capital has started to pour into nuclear fusion startups, as development expands beyond the confines of large-scale government-funded programs. Regardless of technological progress, the nuclear industry faces huge barriers to deployment. The earliest these new technologies will reach the market is 2030. They will all need to deal with social reluctance to deploy novel nuclear technologies and surpass stringent regulatory barriers.
- Geothermal energy is currently reliant on subsurface permeability and heat. This has limited the scale of the industry. New approaches to geothermal involve subsurface engineering so that projects can be developed wherever there is heat – a far less stringent requirement. This can involve fracking to crack rocks (enhanced geothermal systems) or drilling long subsurface loops (closed-loop). Novel geothermal will only succeed with lower-cost, higher-performance drilling technologies. The industry must address issues relating to potential seismic risk, as well as long project development timelines, to scale quickly. Co-producing heat and power and leveraging existing power infrastructure (e.g. turbines, grid connections) could help boost the economics of geothermal projects.
- Post-combustion carbon capture – where CO2 is removed from the flue gas of a traditional power plant, rather than through a pre-treatment step – is the most viable technology option for CCS in the power sector. Second-generation post-combustion capture technologies, which make use of new sorbents, membranes or cryogenic gas separation, hope to deliver capture at a cost of under $50/tCO2, competitive with European carbon prices. Most of these technologies have the drawback that they only capture 90% of emitted CO2, making the power source low-carbon rather than zero-carbon. Reducing the energy requirements for sorbent regeneration and the durability of capture materials will be key in lowering costs.
- Mechanical energy storage relies on winches, pumps and compressors to raise some mass or compress a fluid. To discharge energy, the pressure or weight is released, which drives a turbine to produce power. No fundamental breakthroughs are needed to commercialize mechanical energy storage, as the concept is simple, just more efficient designs and supply chains. Mechanical systems can also provide inertia to the power system that electrochemical storage cannot provide as they have rotational mass. Because of the technology simplicity, the main way to reduce the cost of systems is to scale projects and supply chains. This could make projects very prone to nimbyism, as mechanical systems have low energy density and thus a large physical footprint.