Because the network is shared, how is usage calculated individually?
During the technical visit, we will evaluate each individual home/business to determine and estimate. The evaluation will factor in past utility usage. All 100 customers will not be on the system at the same time. We will size it to be efficient. During the operation of the pilot, we will also be monitoring usage by each heat pump to compare our design vs. actual performance.
If a pipe is damaged, does the whole system go down?
It depends on where the damage takes place. Hits typically happen on service lines located on a customer’s private property, so we would be able to isolate the individual service line. It would not affect the whole system. This is similar to how we respond to hits on our natural gas service lines. If a main line hit occurs, the severity will determine if a repair can be made without shutting down the system.
Who is responsible for maintenance? Do customers have a choice of who maintains their equipment?
Eversource will perform the maintenance of the geothermal equipment for the duration of the pilot project. Once the program is finished, the equipment maintenance will be the responsibility of the property owner.
If the pipes last 50 years, who is responsible for the cost when they need to be replaced?
The system – including the pipes – will be owned and operated by Eversource. Eversource is responsible for the pipes and replacing them if needed.
We estimate the pipes will last 50 years. We will be using HDPE plastic pipes, the same type we use for gas; currently, many in use are older than 50 years.