Tilly Foster Farm & Conservation Area is 199 acres of a scenic complex of pastures and historic farm buildings located at 100 Route 312,Brewster,New York.  PutnamCountypurchased Tilly Foster Farm and Conservation Area in October of 2002. The farm is dedicated to conserving agricultural productivity, water quality protection, open space character and community environmental education while providing the residents ofPutnamCountywith recreational activities. It is open to the public year round and offers trails for hiking and cross country skiing, equestrian services, a small historical museum, a public organic community garden and is home to a small group of rare and endangered heritage animals.

The impetus for the installation for solar power system at the farm came from the members of the  Tilly Foster Advisory Board. Installing a solar power system at Tilly Foster Farm was consistent with the vision to evolve Tilly Foster Farm into an education farm for the public and an opportunity forPutnamCountyto demonstrate it’s commitment to energy conservation.

It is always a challenge for municipalities likePutnamCountyto implement  green energy measures because of the initial costs and concerns regarding  payback.  To offset the cost of a solar power system the County sought out grant opportunities with New York State Energy Research and Development Authority (NYSERDA).  The grant process and the installation of the PV system were administered by the Putnam County Purchasing Department.


Table of Contents Downloads
Solar Project Intro
-RFP Process
Net Metering
Education and Outreach Plan
Resource Links
Photovoltaic Brochure
Diagram for Tilly
Tilly Solar Electric System




While the New York State Energy Research and Development Authority (NYSERDA) has ongoing incentives for the installation of photovoltaic (PV) systems, a unique 1.3 million dollar funding opportunity became available under Program Opportunity Notice (PON) 969. Funding for the project was from a settlement of a lawsuit by the New York State Attorney General against the Ohio Edison Company.  This program was earmarked for the installation of solar power systems exclusively onNew YorkStatemunicipally owned buildings and earmarked $500,000 specifically for counties that borderedConnecticut.

The submission of the grant was a joint effort, byPutnamCounty’s Departments of Purchasing, Department of Planning & Transportation and Parks Division of Highway & Facilities with assistance from PV design consultant, John Calhoun, PE.

The maximum reimbursement from NYSERDA for this project  was $84,500 which offset approximately 80% of the cost of the project. As a recipient of the grantPutnamCountywas required to match twenty percent of the cost of the PV systems.  PutnamCountyfulfilled the matching commitment with in kind services.

This substantial grant funding from NYSERDA was critical in the decision forPutnamCountyto move forward with the solar project.  Partnering with NYSERDA with this grant presentedPutnamCountyan ideal opportunity to take the next step in becoming energy efficient and offer an alternate energy source for a county facility.




Once the funding was in place design consultant  John Calhoun, PE developed a preliminary design and prepared project specifications based on the farm’s electricity use patterns and the physical layout.

The horse barn, which contains the Power Conditioning System (PCS) equipment, is located at the main entrance to the Tilly Foster Farm and Conservation Area along with several offices, educational and support buildings.  The utility electric service is distributed throughout the campus from the 120/240VAC, 200A service entrance in the barn.  A storage room in the barn will be dedicated to the PCS equipment and interpretive items related to the PV system.  It is adjacent to the main electrical room, allowing simple conduit routing to the interconnect point.

Electricity from the PV system partially displaces purchases of utility power to the cluster of buildings located off the main entrance at the Tilly Foster Farm and Conservation Area .   The PV array was placed in an open field approximately 700 feet from the barn in an area with no obstructions and no shade.  The array faces south at an optimum 40 degree tilt.  The ground-mounted array and its interpretive display border a primary hiking and skiing trail for easy public access.  Conductors from the array to the PCS are installed in an underground along this trail.



In February 2008 the Purchasing Department issued an RFP for a NYSERDA approved, photovoltaic (PV) system contractor to install a 13kW, grid-connected PV system.   After an extensive evaluation process, the contract was awarded to:

HudsonValleyClean Energy, Inc.
13 Hook Road


The project began in July 2008. Hudson Valley Clean Energy worked closely withPutnamCountyand consultant John Calhoun, PE throughout the project.  The Parks Division of the Highway & Facilities Department provided all the labor, material and equipment necessary to complete the trenching, concrete footings and interior renovation of the barn to accommodate the installation of the switches.

Hudson Valley Clean Energy installed a Sun Power 225 Solar Panel. The PV system consists of 56 225 Watt solar modules  mounted on 7 poles. The PV system interconnects with the NYSEG utility grid.

The 13,000W array consists of fifty six  225W solar modules.. The PV modules are ground-mounted on a commercial rack with concrete footings.  The structure is approximately 11 feet high and 70 feet wide.   Conversion of the PV array’s DC output to 240VAC and automatic control of system operation is accomplished with two 6000W and one 2500WSMAinverters.  The PCS  also include AC and DC disconnects switches, lightning protection and an energy production meter.  The PV system has a nominal DC rating of 13,000W.  With typical conversion losses the AC rating is approximately 10,000W.

The installation was completed in August 2008.  The final NYSEG inspection was completed in fall and the system went live October 2, 2008.

Under typical weather conditions the 13kW PV system should produce 15,840kWh per year, 33% of the building’s annual electrical consumption based on the 2005 billing history.

Prior to installing installation of the net meter we have saved approximately $2,000.00.

Attachments:   Diagram of Photovoltaic Generating System �
Information on systems


Net metering is a policy that allows owners to receive the full value of the electricity that their solar energy system produces. Net metering offsets the electric bill with any excess electricity they produce because if more electricity is produced from the PV system than required the extra kilowatts are fed back into the utility and the meter runs backwards.

In February of 2009 municipalities inNew YorkStatebecame eligible for net metering. NYSEG installed a net meter in May 2009.


Education and Outreach Plan

One of the main goals of PON 969 was to foster a market for PV systems and to provide the public with an opportunity to learn about PV systems. Tilly Foster Farm & Conservation Area is open to the public every day of the year and the installation of a PV System is consistent with the vision to evolve Tilly Foster Farm into an educational farm for the public

To foster education on the use of PV energy we have an on-site informational Bulletin Board with a digital output meter and are in the final stages of installing an additional informational Kiosk.

To ensure that all local residents, businesses, school officials are well  informed on the PV system we have NYSERDA informational brochures for distribution at Tilly Foster Farm & Conservation Area , the Putnam County Office Building  and at other County owned facilities.

In October 2008 Preserve Putnam hosted a Livable Communities which highlighted the Solar Power system at Tilly Foster Farm.



For additional information on solar energy visit the following sites:

To learn about alternative energy sources and incentives and funding opportunities please visit:


While the return on the investment is not immediate,PutnamCountyhas invested in the long range fiscal and environmental future ofPutnamCountywith the installation of the PV system at Tilly Foster and we are confident it will encourage both homeowners and businesses to make green choices in the future