Lecture Notes: Solar Installations and Home Battery Systems

Introduction to Batteries in Solar Systems

• Many homes have solar installations but lack a battery.
• Adding a battery can bring significant benefits.
• Increasing battery size can enhance these benefits.

Solar Generation and Consumption Profiles

• Typical Daily Solar Generation and Usage:
  • Morning: Peak due to appliances like toasters, kettles, and hair dryers.
  • Midday: Low usage, high solar generation.
  • Evening: Another consumption peak with appliances such as ovens and dishwashers.
• No Battery Scenario:
  • Morning and midday covered by solar generation.
  • Evening consumption requires grid energy.
  • Midday excess solar generation is wasted unless manually used or exported.

Benefits of Adding a Home Battery

• Load Shifting:
  • Excess solar energy charges the battery midday.
  • Battery discharges in the evening, reducing grid dependency.
  • Considerations for battery size include solar array size, inverter power, and daily usage.
  • Maximum charge/discharge rates are crucial to meet home demand efficiently.

Utility for Battery Sizing

• A tool to model solar and battery setups based on usage profile.
• Example configurations:
  • Non-solar household: 15 kWh/day at 30 pence/kWh.
  • Adding solar reduces bills, and further reduction seen with a small battery.
• The impact of battery shows reduced grid import and increased savings or profits.

Time of Use Tariffs

• Smart meters enable tariffs with varying rates based on usage time.
• Example: Octopus Energy's smart tariffs.
  • Tariffs like Octopus Go offer cheaper rates during off-peak hours.
  • Batteries can be charged during these times to reduce costs.
• Example calculations demonstrating cost reduction with battery and tariff changes.

Plunge Pricing

• Global energy trends show increasing wind and solar contributions.
• Challenges: Balancing supply and demand with fluctuating renewables.
  • Over-forecasting leads to surplus energy, resulting in plunge pricing.
  • Octopus Agile Tariff: Tracks wholesale prices, enabling savings during price drops.

Demand Flexibility Schemes

• High demand scenarios can prompt coal use, but demand can be managed through flexibility schemes.
• Octopus Energy Trials:
  • Consumers paid to reduce usage during peak times.
  • Battery owners can benefit more by participating in these schemes.

Virtual Power Plants

• Home batteries can become part of large distributed systems (virtual power plants).
• Potential for profit sharing by participating in these setups.

Conclusion

• Batteries provide significant advantages in optimizing solar energy usage.
• Future discussions will cover ideal battery considerations.
• Thank you for the support in educating about solar technology.