Rotten Point House

100% carbon neutral

A detailed system design was completed. Meter interval data for the site was received and a yearly demand of 33,300 kWh was determined. Yearly simulations based on NASA wind speeds, temperature and solar radiation estimate the final system’s yearly generation to be 33,739kWh/year. Providing a carbon negative solution. (20087kWh/year PV, 13,652kWh 5.1kW wind)

Utilization of the cement slab as thermal energy storage. This was achieved by automation of resistive in floor heating + heat banks through AWS SunMate power diverters and thermostat optimization. The power diverter reads excess renewable energy generation and automates the load with variable power outputs. When the required temperature is met in one circuit, the SunMates divert power to the remaining in floor heating circuits, when the slab reaches temperature, excess power is used to charge batteries or is fed to the grid. The inclusion of power diverters help to reduce battery cycling and increase efficiency of the system.

Backup power

Grid failures are common place and as this home is a holiday rental, reliable power is essential for customer satisfaction. Backup power was achieved via the installation of 2 x Tesla Powerwall 2 battery banks with backup gateway. The utilization of power diverters to control in floor heating frees energy storage capacity to allow backup power for essential loads such as water pumps and lighting during a blackout. The inclusion of a wind turbine also increases night time backup power by providing continuous generation.

 

Tesla Destination charger

More and more clients own electric vehicles so the inclusion of a charging portal is essential.

 

Load shedding of in floor heating during a blackout

Load shedding was required in order to reduce the demand on the batteries during periods of extended blackouts. Backup power is important as all water and toilet plumbing is powered by water pumps. Grid failure means no water and removes the ability to flush the toilet. Load shedding was achieved via the use of rewiring of the in floor heating onto a single phase, that was not connected to the backup circuit from the PowerWalls.

Wind Power

The next step in this project is to add an AWS HC 5.1kW wind turbine to the current system.

Links

For more information on Rotten Point House, or to book accommodaton, click here