Early Design Considerations for Future Installations
Certain systems should be designed early in the build process to ensure that their future installation is both quick and cost-effective. Key among these are rainwater harvesting systems and solar panels (photovoltaics PV for electricity, solar thermal for hot water, or hybrid panels that do both).
Rainwater Harvesting Systems
Ireland typically experiences ample rainfall, but in some regions, the mains water supply is under significant pressure due to high demand. Rainwater harvesting is an environmentally friendly and cost-effective way to use rainwater for tasks such as watering your garden or washing your car, especially if you plan your external roof water drains correctly from the start.
Managing Water Quality
Stored rainwater can become stagnant if left unused for too long. Regular usage and replenishing with fresh rainwater will help maintain water quality.
Integration with SUDs Systems
To enhance rainwater management, the storage system can be linked to a Sustainable Urban Drainage System (SUDs), which helps manage rainwater buildup over hard surfaces. More complex systems may incorporate storage tanks and pumps.
Potable Water Conversion
It is possible to convert rainwater into potable water using particulate filters, UV sterilization, and carbon filters. However, these systems are costly and are generally only viable where there is no other source of drinking water.
Solar Energy Systems
Solar energy is another option to consider. Photovoltaic (PV) panels generate electricity during daylight hours, peaking on sunny summer days. This is ideal if your energy consumption aligns with this pattern. However, most people’s energy usage peaks in the early morning and evening, when PV output is low.
Micro Hydroelectric Systems
If your property is near a stream or river, you might consider a micro hydroelectric system, which can produce electricity continuously throughout the day and year-round. Be aware that you may need permission from the water authority to install such a system.
Exporting and Storing Excess Electricity
Exporting excess electricity to the grid is possible in both NI and ROI, but the compensation is minimal. A practical alternative is using the excess power to heat water via an immersion heater. However, solar thermal panels are much more efficient for this purpose.
Challenges of Electricity Storage
Electricity is difficult to store efficiently, and energy losses can be significant, even with a battery. While the payback period for PV systems has been dropping due to technological advances and economies of scale, the real game changer will be low-cost battery storage.
Battery Storage and Electric Vehicles (EVs)
Batteries allow you to store electricity until you need it and can also facilitate fast charging for electric vehicles (EVs). EV chargers are now mandatory in all new builds, and grants are available to support installation. However, factors like efficiency (e.g., depth of discharge) and product longevity are currently limiting widespread adoption. Additionally, the chemicals in batteries can pose recycling challenges.