Paying for Boreholes & Building Retrofits with Bonds

Troy NY’s geothermal network - The city is installing boreholes under one of its parking lots to sell thermal energy to National Grid's geothermal network.

Troy NY’s geothermal network - The city is installing boreholes under one of its parking lots to sell thermal energy to National Grid's geothermal network.

Massachusetts gas utilities currently spend $1 billion per year installing new gas pipes.  Under the new 2024 Climate Law, these utilities will be encouraged to redirect some of the money to installing geothermal networks in order to reduce emissions and stranded assets. 

To further enable this clean energy infrastructure, HEETlabs is proposing that the Commonwealth allocate a portion of its upcoming environmental bond bill to drilling boreholes under state and municipal property, near where a utility plans to install a geothermal network. 

Each local utility can then operate the distribution system and bill its customers the way it normally does, while paying the state for the thermal energy the boreholes deliver.  This ongoing revenue can repay the bond over time. In the end, everything from the infrastructure to the cost of the capital is funded by the ratepayers through their energy bills.

And that cost of capital over time adds up. Massachusetts gas utilities currently pay an average pre-tax rate of return of 9.11% per year. If the boreholes for a street cost $10 million, the infrastructure’s weighted average cost of capital over 30+ years of depreciation would total an additional $15 million—more than the original cost of the infrastructure.  

With a government bond, the state’s cost of capital would be less than half of that. This much lower cost of capital means that the state can spend approximately $5 million on building retrofits, along with the $10 million on the boreholes, without increasing the total cost for the ratepayers. The building retrofit funding can pay for heat pumps, appliances, etc., to ensure that all residents can connect to the geothermal network in an equitable way.

The Commonwealth issuing a bond for boreholes, while allocating the avoided cost of capital to building retrofits, will jumpstart the critically important transition from methane gas to clean, renewable heating and cooling with equity, speed and scale. This innovative financing model will also help the state meet its net zero emissions mandate and can serve as a model for other states seeking to advance the clean energy transition.

Customer Interest

In Eversource’s geothermal network installation in Framingham, when the retrofits were free, every customer contacted, except for one, agreed to connect.  That one customer had just replaced his HVAC.

Applicability

Ten percent of all the land in Massachusetts is owned by the Commonwealth. Additionally, municipal streets are co-located with buildings. Thus, it’s not surprising that the three Massachusetts geothermal network pilots currently being designed or installed have all of their boreholes located under state and municipal property. 

Affordability

The Department of Public Utilities (DPU) will calculate the total amount of debt that can be incurred at the state’s interest rate such that the total cost is the same as if the utility installed the boreholes with its cost of capital over the payback period. The DPU will also set the customer bill and the cost of the state’s borehole energy such that affordability is maintained. Currently, economic analyses predict that customer bills from geothermal energy will be the same as, or lower than, with gas.

Long-term Revenue

Since boreholes and thermal pipes have a hard warranty of 50 years and most bonds are for 30 years or less, the state will continue to receive revenue long after the bond period is over.

Interest Rates

While interest rates change over time, American utilities’ weighted average cost of capital in inflation-adjusted dollars has stayed at close to 10% for the last 20 years, while long-term government bonds have stayed under 6%.

Reducing Expensive Electric Upgrades 

Geothermal networks reduce winter electric peak load by up to 70% compared to buildings on air source heat pumps. Thus installations can be sited to reduce the need for additional expensive electric substations and local grid upgradess

Reliability

Unlike wind or solar power, geothermal networks deliver non-intermittent renewable energy. And because the infrastructure is below ground, it is protected from severe weather events, which in turn would protect the state’s investment.

Draft Legislative Language for the Bond Bill Line Item

EXECUTIVE OFFICE OF ENERGY AND ENVIRONMENTAL AFFAIRS
Office of Energy Transformation

For the installation of state-owned geothermal boreholes on Commonwealth or municipal property, such as the public right-of-way and parking lots, so that such boreholes may provide and sell non-combustion energy to local utility-owned thermal networks in furtherance of the Commonwealth’s emissions reduction goals; provided, that the installation, operations and maintenance of such boreholes is performed through a pre-authorized drilling contractor following all local laws and regulations under the guidance of the Department of Public Utilities; provided, that, upon installation, the Department of Public Utilities calculates any savings from the difference between the cost of capital over the full payback period of the Commonwealth’s amortized bond and utility’s weighted average cost of capital; provided, that the funds equivlent to the calculated savings be directed into a fund (to be known hereafter as the Geothermal Transition Fund) to pay for local buildings to be retrofitted so that such buildings can connect to the thermal network; provided, that such work be performed with the permission of such buildings’ owners and under the auspices of Mass Save; and provided further, that the price for the energy sold to the utility-owned thermal network is set by the Department of Public Utilities, and such funds are directed to the Geothermal Transition Fund at the Office of Energy Transformation to pay down the debt service for the bond. ................................................$200,000,000