Deep Energy Retrofit and PV - Somerville - MA

Multi-Family Residence - January 2010

Quick Facts

Average Annual Savings

$930

Energy Needs Met

100%

or more of electricity

Net Investment

$18,473

Return on Investment

5.0%

Property

Type:: Multi-Family Residence
Address:: 30 Sycamore St #2, Somerville, MA 02143
Size:: 2,986 sq ft
Energy need met:: 100% or more of electricity
Designations:: Deep energy retrofit

Technology

Type:: Solar PV
Installed:: January 2010
Size of System:: 5.25 kW
Purposes:: To generate electricity

Financial Details

Gross Cost of System:: $36,773
Value of Rebates:: $12,000
Value of Tax Credits:: $6,300
Net Cost of System:: $18,473
Annual Savings:: $930
Own or Lease:: Cash Purchase
Additional Financial Notes:: The 5.25 kW DC system produces around 6200 kWh AC per year. This equals $930 annually at $0.15 per kWh. The 2 family house consumes around 4500 kwh annually, so we are a net producer of around 1700 kWh for combined units

Professionals & Suppliers

Products:: Solectria Renewables; KYOCERA Solar, Inc.
Installers:
Builders:: Byggmeister Associates, Inc.
Energy Auditors:: Energy Efficiency Associates, Mike Duclos

What You Need to Know

Description:

Deep Energy retrofit and Grid Tied PV

Other Benefits:

The DER has reduced our heating and hot water use from 250 MMBtu to 100 MMbtu annually.

Maintenance Requirements:

None so far.

Efficiency or Sustainability Improvements:

Spray Foam Closed Cell Deep Energy Retrofit: o new windows on the outside of the wall without removing the existing wood double-hung windows. The charm of the old glass and wood trim is preserved from the inside and the new, energy efficient windows are in the same plane as the siding on the outside. o Installed four inches of closed cell foam to the outside without removing the existing siding by using wood framing spaced away from the house with foam blocks. o I replaced the two existing boilers and two water heaters with one Buderus condensing boiler with an indirect heated hot water storage tank. Before the energy improvements, Mike Duclos of Energy Efficiency Associates (www.eeassociates.com) modeled the house and gave it an unofficial HERS Rating of 120. With the building envelope improvements is has a HERS rating of 52. With the solar PV it has a HERS rating of 37.

My Motivation:

My motivation was to create a comfortable, durable home with a low energy use.

Experience with Installer:

Excellent

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