OPA SPORTS-CORE POOL ENERGY COSTS: REDUCTION STRATEGIES · OPA Sports-Core Pool Energy Costs: Reduction Strategies then concentrates again during non-use. A comparable system is also

1 OPA Sports Core Pool Energy Costs: Reduction Strategies

June 30, 2011

OPA SPORTS-CORE POOL ENERGY COSTS: REDUCTION STRATEGIES

Sports-Core Pool South Side (facing Veterans’ Memorial)

Prepared and Submitted by the OPA Environment and Natural Assets Advisory Committee with consultation from other OPA officials and other private service providers.

2 OPA Sports-Core Pool Energy Costs: Reduction Strategies

Introduction In October 2010, the OPA Board asked the Environment and Natural Assets Advisory Committee to help evaluate the potential of solar energy to reduce energy costs for the Sports Core Pool. This report describes the Committee’s evaluation of the requested solar energy considerations as well as other potential energy reduction techniques. This study involved many contributors, including representatives of OPA Public Works, Parks and Recreation, the Controller, the Aquatics Advisory Committee, and a committee similar to ours studying solar power for the Community Center at The Parke (See Appendix A). Energy Costs Energy costs to operate the Sports-Core Pool year-round run approximately $120,000/year. Seventy percent of the cost is propane ($85,000/year). Thirty percent ($35,000/year) is electric power Table I (see page 16) shows detailed energy usage and costs by month and day for calendar year 2010. Propane use is highly seasonal, as illustrated in Figure 1, which uses the Table 1 data. For example, in January, propane use is 18 times the use in July. Most of the propane goes to heat the air in the building during the wintertime. On the other hand, electric energy use, also shown in Figure 1, is nearly constant. Electric energy used in January is only 1.3 times that used in August. Most of the electricity goes to the HVAC system to de-humidify and ventilate the air. Energy Loads: What the Energy Does The U.S. Department of Energy’s initiative to Reduce Swimming Pool Energy Costs1 has concluded that 70% of the energy costs at a typical indoor pool are due to evaporation of water from the pool. This includes: evaporation followed by de-humidification, which involves refrigerating the building air, followed by reheating the air. Ventilation accounts for 27% of the energy costs at a typical pool. The energy cycle at the Sports-Core Pool is as follows: • As the water evaporates, it removes energy from the pool. To keep the pool warm,

this energy of evaporation is replaced by a propane heater, which in normal operation uses about 2% of the propane used at the facility.

1 http://www.iamu.org/waterwise/Documents/RSPEC - Indoor Pools.htm


• This water vapor must be continuously removed from the air. The relative humidity inside the building must be maintained around 65% to prevent condensation on the roof and walls that could damage the structure and void the warranty on the building. This de-humidification is accomplished by chilling the air below its’ dew point to condense the water vapor.

• After the air is chilled to de-humidify it, it must be heated back to the desired temperature around 84 degrees F.

The actual volume of pool evaporation is known only approximately. Estimates of evaporation rate range from tens to hundreds of gallons/day. Strategies to Reduce Energy Costs This report discusses possible ways to reduce the amount of energy needed and to make the required energy cheaper, particularly with solar energy. These approaches, illustrated schematically in Figure 2, include: • An energy audit, possibly leading to upgrading the efficiency of the HVAC system. • Natural gas instead of propane to reduce heating costs. • A pool cover to reduce the amount of evaporation from the pool, and thus reduce the

amount of de-humidification, ventilation, and reheating the building air. • A solar hot-water system to reduce the cost of heating the pool water. • A solar electric system to reduce the cost of electricity to de-humidify and ventilate

the building. • A solar heating system to reduce the cost of heating the building.


Energy Audit and Analysis of Possible HVAC Efficiency Upgrades Public Works and Aquatics continually monitor and upgrade pool operations to control energy costs. For example, to minimize HVAC loads during the summer, Public Works is considering a flashing light to indicate when the outside air is so humid that opening the roof vents would increase HVAC energy use. Also, Public Works plans to install a flow-meter to measure the amount of water that the dehumidifier pulls out of the air. This information will facilitate adjusting operating conditions to further reduce electricity and propane use. This work could be supported and augmented by an energy audit to analyze operating conditions and adjustments that could reduce energy use and to identify and evaluate cost-effective upgrades to improve the efficiency of the HVAC system. The results could also be useful to compare with solar energy costs and savings when making investment decisions. Working under general guidance of OPA Public Works, the audit effort should be conducted by an entity that has experience in analyzing indoor community pools and associated HVAC equipment with no financial interest in the audit results. Several independent auditors with pool experience, and approved by the state of Maryland are listed in Appendix B. Liquid Pool Cover To Reduce the Cost of Evaporation and De-Humidification The U.S. Department of Energy’s initiative to Reduce Swimming Pool Energy Costs1 says: “It is highly recommended that the first step to cutting pool energy loss be the evaluation of the economics of using a swimming pool cover.” Until recently, a swimming pool cover involved a constructed solid material product that physically, through manual and/or automated means, was used to cover the pool surface area during periods of non-use. Considerations for this type of cover include: cost investment for the cover itself (varies based on type of cover), level of effort to put on and take off, and the capacity to store the cover during non-use. By way of example, Salisbury University reports that they installed a pool cover several years ago and because of the effort needed to put it on and take it off, it is rarely used. A recent alternative to a constructed cover is a liquid product added to the pool water that creates an invisible layer on the exposed pool surface, reducing heat loss and evaporation; essentially a liquid solar blanket. The leading liquid pool cover product is HeatSavr2, manufactured by Flexible Solutions, a Canadian based company. Product composition is predominantly isopropyl alcohol (95%) and is invisible, bio-degradable, non-corrosive, and non-irritating. The Parke community within Ocean Pines is currently investigating this option and has a proposal under consideration with Solar Energy Services, a Millersville, MD company who would set up and maintain the pump to disperse the product and provide the product inventory through a five year contract. A programmable pump (EcoSavr) would disperse 4 ounces of HeatSavr (the volume of product added is dependent on pool size) into The Parke pool daily at closing time. The product’s greatest effectiveness is when the pool is in a state of non-use. The invisible blanket dissipates during pool use and

1 Please see footnote on previous page 2 http://www.liquidpoolcovers.com/pdf/HeatsavrMSDS.pdf


then concentrates again during non-use. A comparable system is also under consideration for The Parke’s spa. The estimated cost for the EcoSavr system for the OPA Sports-Core pool is $1,200 (one time investment) and 28 gallons of HeatSavr annually (10 ounces daily), approximately $1,900. The estimated return on investment for The Parke would be 11 months. Additional studies are necessary to determine the return on investment for the OPA Sports-Core pool. For comparison purposes, the estimated cost for The Parke is $1,900 (one time investment) and $720 annually for HeatSavr (for both pool and spa). Should The Parke proceed with the liquid pool cover, they will be the first pool in the State of Maryland to do so3. In anticipation, The Parke has successfully navigated the approval process with local and State government officials (most notably the State Health Department and the fire department) and insurance under writers. Solar Energy Options General Considerations The pool building faces south with almost no shade, which is usually ideal for solar power. However, Structures Unlimited, the company that designed and built the pool building, strongly recommends that solar panels should not be installed on the roof, so as to preserve the integrity of the Kalwall roof panels. This leaves two possible configurations for solar panels. Either of these configurations appears to be allowed in Worcester County’s draft zoning regulations for solar panels. • Panels could be elevated like a sunshade over the

patio beside of the building, as illustrated in Figure 3, provided by Green Energy Design, an Easton, MD company.

• Panels could be mounted on the ground, like the panels for the Talbot Community Center beside Route 50 in Easton.

Solar Electric Solar photovoltaic electric power generating systems, which powered spacecraft in the 1960s are now powering commercial buildings on Delmarva. A local example is the Talbot County Community Center, which recently installed a large solar array along Route 50 near Easton. These solar panels will generate about 700,000 kilowatt-hours/year (about 7 times the size of the system considered for the Sports Core Pool). Talbot County used to pay Choptank 14 cents/KwHr. The county will now pay 6.9 cents/KwHr for the solar energy generated in the first year, with an escalator of 3 percent per year for the next 20 years. These cost savings are made possible by substantial State and Federal grants and other incentives.

3 The use of HeatSavr has been confirmed in the Virginia Beach area, the closest to Ocean Pines.

Figure 3. Photovoltaic panels over a patio.


Figure 4. Ground mounted array located in field on west side of building.

In a feasibility study for the Sports-Core Pool, Flexera, a Delaware based company, proposes a system that would generate 30% of the electric energy for the Sports-Core Pool. The system’s projected performance for 25 years is based on a widely accepted US Department of Energy computer model called PV Watts V2. The system would include 312 solar panels, each about 3ft x 5ft, an array of 4680 sq ft. Finding an acceptable location for a large solar array will be a problem. Four alternative locations are:

1. Configure it as a patio shade (like Figure 3) and locate it on the south side of the building. This would minimize the visual impact of the array, but might make too much shade inside the building on winter days. Also this would involve additional expense for the overhead structure. We do not have a layout of this option.

2. Install a ground-mounted

array in the field west of the building (illustrated in Figure 4). This would be highly visible, and, depending on the exact location, might require removal of some of the smaller trees planted along Cathell Road.

3. Install a ground-mounted

array beside the building on the north side (Illustrated in Figure 5). This location would require removal of the large tree beside the pool building, and a dozen smaller trees planted along Cathell road.

4. It might be

feasible to locate a ground-mounted array on the other side of Cathell Road. Although we do not have a

Figure 5. Ground mounted array beside the building. (Grey areas indicate

shade from building.)


Figure 6. Cash flow forecast from Flexera’s feasibility study. Does not include OPA expenses for taxes, insurance, operations & maintenance, and administration of SRECs

layout of this location, this might have the least visual impact of the four options. Being across the road from the pool would require additional installation expense to drill under the road to install the electrical connections, and may also require tree removal.

The following cost estimate is based on a ground-mounted array near the building, i.e., option 2 or 3. The proposed system would cost approximately $327,000. After subtracting a Federal grant of $98,000 and a State grant of $36,000, the net installed cost to OPA would be approximately $193,000. These costs do not include OPA expenses for: taxes, insurance, operations & maintenance, security, and administration of SRECs (described below). The solar electric system would generate income from five sources:

1. The Federal Income Tax Credit of $98,000. 2. The State grant of $36,000. 3. The annual savings on our Choptank bill for energy no longer used, because it

would be replaced by energy from the solar panels. This energy savings is forecast to be about $9,000/year.

4. Money earned by selling Solar Renewable Energy Credits (SRECs). SRECs are mandated by Maryland and other states to encourage utilities to generate or buy solar renewable energy. This income is forecast to be about $33,000/year for 5 years and then gradually diminish to about $2000/year by year 14. Our earnings from selling SRECs would be subject to Federal Income Tax. An estimate of this annual tax is not included in this cost estimate.

5. Reduction of Federal Income tax liability due to depreciation of the investment in the solar electric system. This reduction in tax liability would be about $30,000 in the first year, and would phase out in a few years. We do not know whether OPA could apply this reduction in tax liability to other OPA taxable income besides SRECs.

The cash flow from energy savings and from sale of SRECs is about $42,000/year initially. If the reduced tax liability due to depreciation is also included, the cash flow is about $60,000/year initially. These estimates lead to payback in 3 to 5 years, depending on whether OPA uses the reduced income tax liability due to depreciation. In either case (see Figure 6), the cash flow gradually diminishes to about $37,000/year after 6 years, and to $15,000/year after 12 years, as the value of SRECs diminishes.


Note: Not included in Flexera’s cost estimate are additional expenses such as: taxes, insurance, operations & maintenance, broker fees for selling SRECs, etc. To include these, OPA would need to prepare its own cost estimate. An uncertainty in a solar electric system involves continuing financial incentives and possible legislative changes. However, Flexera offers that their contract would stipulate that OPA would not be charged the amount of the $98,000 Federal income tax credit until Federal cash is in hand. To retain our tax-exempt status, OPA would have to be sure that the taxable income from the solar electric system doesn’t exceed 50% of OPA income (which doesn’t appear to us to be a problem). Alternatively, OPA could form a subsidiary taxable corporation to operate and collect income from a solar electric system. Selecting the 30% capacity for the solar electric system is somewhat arbitrary. A system smaller than analyzed in this feasibility study would cost less and the array of panels would be easier to accommodate at the pool, but the payback time would increase. In summary, the feasibility study indicates that a $193,000 investment in a solar electric system could pay for itself in 3 years, and thereafter continue to save about $9,000/year on our Choptank bill, plus earn several thousand dollars/year from sale of SRECs. If OPA decides to proceed with a solar electric system, this estimate should be expanded to include our plans for: taxes, insurance, operations & maintenance, administration of SREC sales, and ensuring that the financial incentives will be there when we apply for them. Selected solar energy resources on the web are contained in Appendix C. Potential sources for a solar electric system include Flexera, Green Energy Design, and Solar Energy World. Contact information is provided in Appendix D. Solar Hot Water to Heat the Pool Heating the pool water is a smaller part of the propane cost, so using solar energy to heat the pool water would displace a smaller part of the propane use. Given the unavailability of the roof for solar collectors and the cold climate weather in our area, the approach needed for a solar pool heater would use a non-freezing heat transfer fluid (glycol) in a separate loop to transfer heat from solar collectors to a heat exchanger to warm the pool. The existing plumbing at the Sports-Core Pool appears feasible for adding such a solar heating system to supplement the existing propane water heaters. However, a solar water heater would add complexity to the existing heating system. Solar water heaters are not eligible for most of the multiple financial incentives that are available for solar photovoltaic electric power generation. Thus a solar water heater would save less money than solar photovoltaic electric power generation but the amount of the savings would not be subject to the legislative uncertainty and accounting/legal complexity of Government incentives.


Eastern Shore Solar officials, based in Salisbury, MD provided a proposed system that would reduce annual propane usage by 176 gallons, translating to a savings of 27,224 kBtu/year, offsetting current annual propane energy expenses. The solution involves two arrays of seven solar panel collectors. As noted previously, these arrays could not be installed on the Sports-Core pool roof. Suggested locations would be either on the ground or elevated as a shade around/near the south side facing patio. As is the situation with solar electric, albeit to a significantly smaller degree, the location of the solar panel arrays would need to be established and ensure that it is visually appealing. While a reasonably cost effective solution may be achievable, the small amount of propane saved may not justify the increased complexity. Further, as discussed below, the prospect of natural gas in the very near term as an alternative to propane should be first considered. Solar Heating of the Building The Committee did not study solar energy to heat the building. However, active solar heating (which similar to a solar pool heater with a glycol loop) could be considered in the future to supplement heat from propane or natural gas if radiant-heating floor tiles are installed in the pool building. Designing such a solar heating system would require an estimate of how much energy would be needed to heat the floor tiles. Natural Gas Efforts are underway by Chesapeake Utilities increase energy options and provide the infrastructure for the delivery of natural gas to serve Worcester County. At the April 19, 2011 Worcester County Commissioner Meeting, the Commissioners unanimously authorized Commission President Church to sign the Franchise Agreement (Natural Gas Distribution Services) between the County Commissioners of Worcester County, Maryland and Chesapeake Utilities Corporation (Franchisee). The timeline presented by Chesapeake Utilities calls for completing the pipeline and initiating gas transportation services in Worcester County through Eastern Shore Natural Gas (not affiliated with Eastern Shore Gas) by year end 2011. Chesapeake Utilities also reports negotiations with Eastern Shore Gas to provide natural gas to Ocean Pines residents.4 The availability of natural gas could replace the propane used to heat the pool. An initial investment would be necessary to convert with the expectation of a return on investment through reduced energy costs post conversion. Conclusions Energy Costs. Energy used at the Sports-Core Pool costs runs $120,000/year; $85,000 for propane and $35, 000 for electricity. Energy Loads. Evaporation of water from the pool drives the energy required to dehumidify the building. A better understanding of the amount of evaporation and the distribution of energy to dehumidification, heating, and ventilation will help evaluate potential efficiency improvements.

4 http://co.worcester.md.us/minutes/11/Open_04-19-11.pdf


Energy Audit. An energy audit would be useful to assist OPA Public Works in identifying and evaluating possible efficiency upgrades in HVAC. A suitable auditor should have experience in evaluating HVAC for indoor pools. Liquid Pool Cover. A liquid pool cover appears to be promising way to reduce evaporation from the pool, and thereby reduce the electric load and, to a lesser extent, the heating load. Solar Electric. A solar electric system is technically sound and should perform as designed. A disadvantage is finding an acceptable location for the large array of solar panels. Such a system is projected to have a payback time of approximately 3 to 5 years. OPA should do a more detailed cost analysis to include taxes, insurance, maintenance, etc. and should re-evaluate the continuing availability of incentives when a decision is made to proceed with a request for bids. Solar Hot Water. A cost effective solution with a high rate of return, but one that should be re-evaluated towards year end 2011 to assess the status of natural gas. Solar to Heat the Pool Building. While the Committee did not study this concept, if radiant heating floor tiles are installed at the pool, a solar system similar to a solar pool heater could conceptually supplement propane or natural-gas heat. Natural Gas. Natural gas, when available, should reduce the $85,000/year heating bill by approximately 50%. Recommended Sequence 1. Conduct energy audit to evaluate ways to increase HVAC efficiency and thus reduce

the amount of propane (or natural gas) and electricity used, and consider implementing the most cost-effective of these measures.

2. Investigate (and pursue if possible) a means to test a liquid pool cover to assess impact on reducing de-humidification loads and/or consult with The Parke officials to track their status with a liquid pool cover and its’ impact.

3. Solicit bids for a solar electric system after electrical energy loads are minimized by an energy audit and liquid pool cover, if applied.

4. Switch from propane to natural gas when it becomes available. 5. Re-evaluate the potential solar hot water solution towards year end 2011 to assess

the progress of natural gas.


Appendices Appendix A Study Contributors Appendix B Approved Energy Auditors Appendix C Solar Energy Resources via Web Sites Appendix D Potential Suppliers of Solar Electric and/or Solar Hot Water Systems


APPENDIX A: Study Contributors Study contributors include: Kerry Nelson: Director, OPA Public Works ([email protected]) Virginia Reister: Chair, Aquatics Advisory Committee at Sports Core Pool (410-641-7446) Tom Perry: OPA Aquatics Director ([email protected]) Art Carmine: OPA Controller ([email protected]) Steve Habager: The Parke Lead, solar and geothermal energy study (410-208-3504) Vincent Brocato: The Parke Lead, solar study and liquid pool cover activities

(410-208-3337/[email protected]) David Kohler: Contributor, The Parke study Sam Schwartz: Contributor, The Parke study Don Claggett: Contributor, The Parke study Pete Lebel: OPA Sports-Core Pool Enclosure builder, Structures Unlimited, Inc. Jennifer Grasso: Worcester County zoning regulations on solar power (410-632-1200) David Remaniak: YMCA Pool Operator, Chesapeake College


Appendix B. Energy Auditors Maryland Department of Housing and Community Development http://mdhousing.org/Website/programs/RHPP/documents/ENERGY_AUDITORS.pdf The following list represents approved Energy Auditors who expressed interest and confirmed experience related to Ocean Pines’ energy challenges with an enclosed pool. American Property Consultants, Inc. 5901 Hillside Road P.O. Box 98 St. Leonard, MD 20685 Toll Free: 1‐800‐272‐7134 Fax: 410‐586‐1963 E‐mail: [email protected] http://www.hudpass.com EMG 222 Schilling Circle Suite 275 Hunt Valley, Maryland 21031 Telephone: 888‐364‐8258 Fax: 1‐410‐785‐6220 E‐Mail: [email protected] http://www.emgcorp.com EMO Energy Solutions 3141 Fairview Park Drive Suite 450 Falls Church, VA 22042 Tel: 703.205.0445 Fax: 703.205.0449 E‐Mail: [email protected] http://www.emoenergy.com Sustainable Building Partners Attn: Justin Aruck, Director of Building Performance 11325 Random Hills Road, Suite 360 Fairfax, VA 22030 Tel: 703‐225‐3360 E‐Mail: [email protected]


Appendix C: Solar Energy Resources via the Web Maryland Energy Administration: http://www.energy.state.md.us/solar.html Build It Solar: http://www.builditsolar.com/ Solar PV Calculator: http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/ Solar Rating and Certification Corp.: http://www.solar-rating.org/default.htm Maryland SREC Procedures: http://www.srectrade.com/blog/srec-markets/maryland/md-srec-

registration


Appendix D: Potential Suppliers: Solar Electric and/or Solar Hot Water Systems Complete Systems, 2020 Windsor Drive, Suite G2, Salisbury, MD 21801 Contacts: Jeron Holland, owner

Larry Horsman, Sales Manager; 410-677-6773 (o); 443-497-0592 (c); [email protected]

Web site: http://www.completesyscorp.com Eastern Shore Solar, 6288 Westbury Drive, Salisbury, MD 21801 Contact: Ray Emmons, 410-543-1924; [email protected] web site http://easternshoresolar.com Flexera, 22791 Dozer Lane, Unit #8. Harbeson, DE 19951 Contact: Jim Derrick; 302-945-6870 (o); 302-377-6987 (c); [email protected] Ben Farr, VP, [email protected] Web site: http://www.flexera.net Green Energy Design, 31 N. Harrison Street, Easton, MD 21601 Contact: Ryk Lesser, 410-822-5959 e-mail: [email protected] Web site: http://www.greenenergydesign-generalstore.com Solar Energy Services, 1514 Jabez Run, Suite #103, Millersville, MD 21108 Contact: Richard Schroeher; 410-923-6090, ext. 100; [email protected] Web site: http://www.solarsaves.net/ Solar Energy World, 5681 Main Street, Elkridge, MD 21075 Contacts: Jack Bollel; 301-497-3232; 866-856-4580

David J. Navari; 703-861-1088; [email protected] Web site: http://www.solareworld.com


Table 1. OPA Sports-Core Pool 2010 Energy Expenses