Introduction to Renewable Energy

Transition Context: The shift involves moving from fossil fuels (Gas, Coal, Oil) to renewables (Wind, Bioenergy, Solar, Hydro, Tidal, Wave, Geothermal).
Fuel Density Comparisons:
- Diesel: $44.8\,GJ/t$
- Petrol: $48\,GJ/t$
- Coal: $15-27\,GJ/t$
- Barley Straw: $18.5\,GJ/t$
- Willow: $19.15\,GJ/t$
Fossil Fuel Pros/Cons: Advantages include high energy density and historically low prices. Disadvantages include finite supply, greenhouse gas (GHG) emissions, price volatility, and energy security risks.
Renewables Pros/Cons: Advantages include infinite supply and energy security. Disadvantages include intermittency, developing technology states, and planning issues.
UK Electricity Mix (2024): Wind & solar account for $34.3\%$ , Gas for $30.4\%$ , and Nuclear for $14.2\%$ .

Definition: The provision of reasonably priced, reliable, and environmentally-friendly energy. It also refers to secure and affordable supply.
Concepts: Includes import/export status, supply vs. demand balance, and specific security for electricity, gas, and oil.
UK Resilience Measures:
- Maximising UK production.
- Competitive markets and international cooperation.
- Energy efficiency and decarbonisation.
- Reliable networks and smart grids (demand-side responsiveness).

Climate Change Act ( $2008$ ): Originally set an $80\%$ reduction path for sectoral $CO_2$ emissions.
Net Zero ( $2019$ ): The UK government increased the legislated target for GHG emission reductions to at least $100\%$ by $2050$ .
Strategic Needs:
- Extensive Electrification: Doubling current electricity demand, specifically for transport and heating.
- Transport Transition: Transitioning $37\text{m}$ cars and vans and $500,000$ HGVs to low-carbon electricity or hydrogen.
- Heating Transition: All new builds from $2025$ must have low-carbon heating; $29\text{m}$ existing dwellings must switch away from fossil-fueled boilers.

Smart Export Guarantee (SEG) ( $2020$ ): An obligation for licensed suppliers to pay small-scale low-carbon generators (up to $5\,MW$ capacity) for electricity exported to the National Grid.
- Eligible Technologies: Solar PV, Wind, Micro-CHP (up to $50\,kW$ ), Hydro, and Anaerobic Digestion (AD).
Green Gas Support Scheme (GGSS) ( $2021$ ): Provides financial incentives for new anaerobic digestion biomethane plants injecting into the gas grid; participants receive quarterly payments for $15$ years.
Levelized Cost of Energy (LCOE): Costs for Solar Photovoltaic (PV), Onshore Wind, and Offshore Wind have fallen significantly from $2010$ to $2024$ .