SOLAR ENERGY PROPOSAL

SOLAR ENERGY

Prepared for

Melissa Wilke

General Studies Instructor

Northeast Wisconsin Technical College

Prepared by

Tracy Higginson, Jennifer Worden, Roger Hicks

February 6, 2017

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Transmittal Memo TO: Melissa Wilke FROM: Tracy Higginson DATE: February 6, 2017 SUBJECT: SOLAR ENERGY This report presents a proposal to Northeast Wisconsin Technical College in an effort to convince the college to convert their current hot water system to a solar heated water system. Our team has conducted extensive research and our findings revealed a problem of rising electricity and natural gas costs in our community. We are suggesting that NWTC install a solar water heating system on the Niagara campus to determine if a solar water heating system would be a feasible solution for the larger Green Bay campus. By doing so, the college will realize the many financial and environmental solutions that solar energy offers. We hope you will find this proposal informative enough to go ahead with the project and start using our earth’s natural resources in a positive way.

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Executive Summary Our proposal is from a group of environmentally conscientious students at Northeast Wisconsin Technical College. We are writing this proposal to persuade the school to become more environmentally conscientious by installing a solar water heating system at the Niagara campus. The Niagara campus is smaller and will be a test to see if it’s feasible to install the same system on the larger Green Bay campus. We decided to pursue this topic because of the rising cost of electricity and natural gas. It makes financial sense to switch to a more environmentally friendly source of fuel for heating your water. Electricity costs about 16 cents per kilowatt per hour. Natural gas costs about 13 cents per therm and an 80 gallon electric water heater will cost about $870 per year to operate. By switching to solar, you can save $500 per year on just one water heater.

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Table of Contents

TRANSMITTAL MEMO II

EXECUTIVE SUMMARY III

TABLE OF CONTENTS IV

LIST OF TABLES VI

GLOSSARY VII

SOLAR HEATED WATER SYSTEMS 1

THE PROBLEM 1

BENEFITS OF SOLAR ENERGY 1

ENVIRONMENTAL BENEFITS 2 HOMELAND SECURITY 2 TAX BENEFITS 3 PROPERTY VALUE 3

HISTORY 3

PARTS OF THE SOLAR HOT WATER SYSTEM 4

COLLECTOR PANEL 4 TRANSFER MECHANISM 4 STORAGE CYLINDER/TANK 4 ACTIVE/PASSIVE SYSTEMS 4 DIRECT SYSTEMS 5 INDIRECT SYSTEMS 5

COST/SAVINGS 6

MAINTENANCE 6

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CONSTRUCTION 7

CONCLUSION 7

REFERENCES 8

INDEX 10

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List of Tables Figure 1 Solar Energy Exceeds Global Energy Consumption .......................... 8

Figure 2 Peak oil production .................................................................................9

Figure 3 Flat Plate Collector ...............................................................................11

Figure 4 Storage Tank .........................................................................................11

Figure 5 Solar Heating System ...........................................................................12

Table 1 Solar vs. Electric Gas .............................................................................13

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Glossary Absorber/Storage Tank- Constructed entirely of copper, the 4" diameter tubes are welded to the interconnecting pipes to form a series flow pattern. The tank is pressure rated to 300 psi and is coated with a high-temperature ``selective" solar radiation absorption surface that maximizes heat gain and reduces heat loss. Active Solar-Uses solar collectors called solar panels which are primarily used for solar water heating. Uses photovoltaic (PV) cells which make electricity. Also uses concentrated solar power systems or solar thermal systems which make electricity, but on a larger scale (Sclager, 218). Alternative Energy- Non-conventional energy may or may not be renewable, such as solar, wind, geothermal, fusion, and ocean energy (Berinstein, 8).

Fluid Connection- Inlet and outlet connections are made of nominal 3/4" diameter Type ``L" hard copper pipes. This allows for fast, leak-free sweat fitting plumbing connections.

Glazing- Outer glazing is tempered low-iron solar glass with 91% transmittance. Inner glazing is Teflon film, known for its high temperature tolerance (525F) and its long-term durability and stability, transmittance 96%. The 3/4" air space between glazings reduces heat loss.

Therm- A volume of gas containing an amount of energy equivalent to 100,000 BTU’s, measured on a dry basis.

Green Energy- Refers to clean, low, or non-polluting energy such as that from windmills and solar cells. Green does not necessarily mean renewable even though most sources of green energy are renewable (Berinstein, 9).

Insulation- Rigid closed cell polyisocyanurate foam board, the most efficient available, is used to maximize heat retention. Sides and ends of the unit have 1.5" board, R-value 10; bottom has 2" board, R-value 14; between tank tubes has 1.5" board, R-value 10.

Passive Solar- Uses the sun only. No other forms of energy are used. Primarily concerned with design and placement of the building to maximize sunlight gain (Sclager, 217). Renewable Energy- Comes from sources that replenish themselves, such as sun, rivers, wind, and ocean waves & tides. Renewable does not necessarily mean “non-polluting” or “green” (Berinstein, 8).

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Solar Heated Water Systems

This study was conducted to determine the desirability of converting the college’s current hot water system to an environmentally friendly solar heated hot water system. We researched many different kinds of alternative energy sources for the school, but the only feasible option was solar energy. Several factors were considered:

• Benefits of solar energy

• History

• Cost/Savings

• Construction

• Maintenance

The Problem

The main problem is the expense of electricity and natural gas. With costs for both rising annually, it will get more and more expensive to heat water using these fuels. Solar hot water systems can provide facilities with 40-70% of their total hot water needs. Existing hot water heaters will need maintenance of some kind on an annual basis and even more maintenance as they get towards the end of their lifecycle. Solar hot water systems need minimal maintenance annually, which will reduce your maintenance parts and labor cost.

On average schools that go green use 33% less energy and 32% less water than conventional schools (USGBC 10/5/07). In 2001, four schools across the Unites States were requesting LEED (Leadership in Energy & Environmental Design) certification. Today there are 400 LEED certified schools (Green Schools 11/1/07). In 2004 only 6% of United States energy came from renewable sources, and only 3% of that 6% came from solar. Many experts believe that solar power will be the most important alternative energy source in the future (Sclager, 216).

Benefits of Solar Energy

Solar Energy is becoming a reliable way to use our Earth’s natural resources to our advantage. It is an excellent way of using the sun’s energy to power our daily lives. The powerful heat from the sun accounts for over 99% of our planet’s renewable energy resources, and the global consumption of that energy is only a fraction of what the sun is capable of providing. (See Figure 1)

Many different applications use solar

energy such as, lighting, electricity, transportation, air conditioning, and

Figure 1 Solar Energy Exceeds Global Energy

Consumption

Source: en.wikipedia.org/wiki/Sun_energy

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heating. In this particular proposal, we are focusing on the sun’s ability to heat water using its solar power. Over 1.5 million businesses and homes are using solar water in the United States alone, which is becoming an increasingly popular trend in the usage of solar energy.

Environmental Benefits

Every person should be aware of our world’s environmental issues like pollution, ozone depletion, and climate changes resulting in global warming. We must realize how convenient solar energy is and how obtainable it has become. By using solar energy, it increases awareness of renewable energy sources and energy conservation and it is an obtainable economical solution. Becoming environmental leaders is something that each one of us is capable of accomplishing.

Solar heating provides an environmentally friendly alternative to heating homes and businesses. Atmospheric gases, also known as greenhouse gases, are increasing every year which result in rising temperatures, droughts, and the melting of polar ice caps. The major fuels used for water heating include natural gas, electricity, oil, and liquefied petroleum gas. Individuals can reduce the use of these fossil fuels, which will result in the reduction of greenhouse emissions and our dependency on electric and gas water heaters. Solar energy plays a positive role in our environment.

Homeland Security

National security is a concern for every American today and our dependency on fossil fuels threatens our own national security! Natural gas imports have reached an all-time high and are increasing steadily. Unfortunately, a majority of the world’s oil reserves is in the Middle East, and the U.S. oil production has been steadily declining. By the year 2010, predictions are our country’s need for oil imports could rise to 75% and could drastically affect our country’s economic growth1(See Figure 2). With the advantages of renewable energy becoming apparent, we can decrease this dependency and save our country millions of dollars.

By investing in solar energy, Americans will create more jobs and promote economic development. Strengthening our energy security will strengthen national security!

1 <http://www.safehaven.com/showarticle.cfm?id=8819&pv=1>

Figure 2 Peak oil production

Source: en.wikipedia.org/wiki/Sun_energy

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Tax Benefits

In an effort to encourage homeowners and business owners to install solar energy systems, the U.S. government has a federal energy tax credit available. The first 10KW installed will receive up to 50% tax credit, which amounts to about three dollars per watt. After that, they can receive a 30% tax credit at two dollars per watt. These tax credits are available through December 31, 2008 under the Tax Relief and

Health Care Act of 2006, section 2072. State and local grants, along with the federal tax credits, help make solar energy systems financially attractive to business owners.

Property Value

Finally, installing a solar water heater will greatly add value to residential and commercial buildings. Home value increases twenty dollars for every dollar reduction in annual energy bills3. Solar energy provides light and warmth along with a reliable source of hot water in the event of natural disasters or energy shortages. Solar energy can also save homeowners up to 50% of hot water costs per year; therefore, paying for itself within 4-8 years.

History

Solar hot water systems have been available for many years. Their popularity peaked in the late 1970’s and early 1980’s due to federal tax credits and the scare of a national oil shortage. This popularity for solar domestic hot water (SDHW) systems crumbled rather quickly when the Reagan administration revoked the tax breaks in 1986. The large tax breaks and quick popularity of SDHW systems may have hurt their United States market in the end. Hundreds of small SDHW system manufacturers and installers popped up across the country rushing to make a profit on the rapidly growing market of SDHW systems. Unfortunately, many of these manufacturers and installers did a poor job. After revoking the tax credits, and homeowners no longer installing solar hot water systems, most of the businesses went bankrupt, thus leaving thousands of orphaned SDHW systems on roofs across the country.

As these systems malfunctioned often there was no one available to fix them, and most users didn’t know enough to fix the problems on their own. This trend of low quality products, poor installations, and then no service worked together to give the SDHW industry a bad name in many American’s minds. Many of these systems were not aesthetically pleasing as today’s systems. Because so many of these older less attractive systems were installed, and have been visible for many years, this is the image many American adults think of when they hear ‘solar water heater’.

2U.S. Department of Energy, Solar Energies Technology Program-Multi-year

Technical Plan, 2003-2007 and Beyond, January 2004. 3“Cost vs. Value,” Remodeling Magazine. October 1999: 90.

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Parts of the Solar Hot Water System

The solar hot water system consists of three main components:

• Collector Panel- Used to absorb the sun’s rays.

• Transfer Mechanism- Used to move the heated water to a storage tank.

• Storage Tank or Cylinder- Used to store the heated water.

Collector Panel

The most common kind of panel is the flat plate collector panel (See Figure 3). It consists of a flat sheet absorber or envelope of a specially blackened metal. The panel absorbs the sunlight and transfers the heat produced directly to the water, or the transfer fluid, flowing through the panel.

Transfer Mechanism

The transfer mechanism can be either a pump or natural circulation/thermosiphon. Natural circulation or thermosiphon uses the heated water/fluid in the collector panel to produce a natural convection. The cool water/fluid moves down from the storage

tank to the panel and the more buoyant heated water/fluid moves up. With a thermosiphon system, the storage tank is higher than the collector panel with the pipes sloping at a specified angle to ensure proper performance. If you are using a pump, the main advantage is placing the storage cylinder below the panels. This is an ideal setup for people who want to replace their old system with solar. The pump has a control unit. This allows the pump to run only when the water in the collector panel is hotter than the storage tank.

Storage Cylinder/Tank

The storage cylinder is larger in a solar heating application than in other systems (See Figure 4). In times of good weather, it reduces the amount of wasted energy.

Active/Passive Systems

Over the years, various styles and types of solar domestic hot water systems have come and gone from the top of the market. Solar hot water systems either are active or passive. Passive systems have no moving parts and are therefore much simpler. Water circulates through them using only natural convection. They are not as flexible

Figure 4 Storage Tank

Source: solargain.ca./hubley_solar.html

Figure 3 Flat Plate Collector

Source: www1.eere.energy.gov

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as active systems because the water storage must be above or near the collector. These systems are common in more tropical climates. Here in Wisconsin they don’t offer adequate freeze protection, but in the proper climate zone they can be quite effective and economical. Because passive collectors don’t work well in Wisconsin, we will not discuss them further in this paper.

Active systems, which involve some controls and some type of pump, are able to collect a significant amount of energy, but the capital costs are often significant as well. They consist of a flat plate collector or rows of evacuated tubes, one or two storage tanks, a pump to move the fluid through the collector, valves, controls, and usually a backup source of energy (See Figure 5).

Direct Systems

You can characterize all solar hot water heaters as either direct or indirect. In all but very warm climates, direct systems need some form of freeze protection to avoid costly damage to the system when the temperature drops below freezing. The only common direct system is the draindown system. During times of less intensive sunlight, the water in a draindown system drains into the home’s sewer system. This design must allow a small amount of heated water to go unused and down the drain each day (about 2 gallons). The advantage of this system is that it is simpler, and therefore less prone to malfunction, and less expensive than the other common active system options. Today new draindown systems are quite uncommon; the most similar is a drainback system.

Indirect Systems

Indirect systems collect the solar energy in a separate fluid from the potable (pō’ tə-bəl—fit to drink) hot water. These systems must include a heat exchanger to transfer the collected energy from the collecting fluid to the potable water. The main advantage of this type of system is that a collecting fluid, other than the potable water, is used. This is usually distilled water or propylene glycol (glī’ ĸǒl—a form of alcohol). The freezing point of glycol is less than that of water, so it provides excellent freeze protection. Both of these fluids protect the collector and other system components from damage and/or scaling cause by hard water. The system would empty the collector at similar times to a draindown system, but instead of going to the drain, the water would go to a small, insulated holding tank.

When replacing an electric water heater, a SDHW system typically has a payback period of 5-10 years. At current gas prices, the payback period when the solar energy is offsetting natural gas usage is somewhat higher. The exact payback period

Figure 5 Solar Heating System

Source:westnorthfolk.gov.uk/default.wpx?page.com

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obviously is a function of many factors, but perhaps the greatest is how much hot water the household consumes. The more hot water consumed the faster the payback, but also the more money spent on backup heat for the system. Water conservation can have a huge impact on household hot water expenses. Wise use practices and flow restrictors in showerheads and faucets can limit the amount of hot water used. The set point of the thermostat in the water heater also plays an important role in the amount of energy used for hot water.

Hot water heaters often come from the factory set at 135˚F or 140˚F. Unless the house has a dishwasher without an automatic heater, which requires 140° F water, you can set your water heater at 120° F without any adverse effects. Setting the thermostat at 120˚F will reduce stand-by losses in the tank and still supply adequate hot water. In the case of a single-tank SDHW system, the benefits of a lower thermostat setting go even further. In the case of the draindown system, the water sent to the collector is cooler and therefore is able to experience higher net energy gains per pass through the collector. Similarly, in indirect systems, the heat exchanger is able to pass energy more effectively the lower the temperature of the potable water.

Cost/Savings On average, with today’s technology, you will save between 50% & 80% on your hot water (See Table 1). In the future there will be much higher savings. Here is a formula that will help you estimate your savings. Yearly Cost ($) = 365 days * kilowatt hours (kWh)/Energy Factor (EF), by using this formula we found that Niagara campuses would save $494.75 per year on hot water costs.

Maintenance

These systems do not need much maintenance. Most systems need maintenance once every three to five years, but on average, once a year works best.

When you do have to maintain the solar hot water system, you should check all the seals and glazing for cracks. Next, check the supporting structure and roof penetrations for any

cracks and rust. You will need to check all the pipes and wiring inside and outside of the building, for cracks in the insulations. Also, check the pressure relief valves to insure proper working order. Next, inspect the storage system’s insulation, piping, and wiring. More than once a year, you will have the task of cleaning your collector panels. This task may involve washing the dust off, removing leaves and sticks, or keeping the snow off.

Table 1 Solar vs. Electric Gas

Source: www.solardepot.com/r_solar_hot_water.htm

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Construction When installing the solar water heating system there is little construction on the existing building. You will need to install mounting brackets and there will be holes for wiring and pipes. If done properly there is little construction on the existing structure. (If you were to put in an automatic tracking system, this would call for more maintenance then a fixed system) If you purchase a completed system, the installation can be as little as a day, but on average, it takes a week. If you were to construct your own, it would take anywhere from two to three months.

Conclusion

We hope you see the benefits of installing a solar water heating system. We know it might cost a little more upfront, but the savings over time could offset that cost. A solar water heating system will last longer than a conventional water heating system, usually eight to ten years longer. There is less maintenance, which will result in lower maintenance costs. These systems are good for the environment because they don’t emit any greenhouse gasses. There is no pollution or waste of any kind from a solar water heating system. As long as you keep them clean and free of debris your system will work for years and years. There are very little costs for construction, which is a very good for those on a budget.

Everyone needs to take a more active role in saving the environment. We, at NWTC, can set an example of being friendly to the environment and responsible by installing a solar water heating system.

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References Aldrich, Robb. Gayathri Vijaykumar, Cost, Design and Performance of solar Hot

Water in Cold Climate. Http://www.carb-swa.com/Preject/Articles/Solar.pdf. “Cost vs. Value,” Remodeling Magazine. October 1999: 90. Federal Incentives for Renewable and Efficiency. Financial Incentives. July 25, 2007.

E:\solarheat\DSIREIncentivesbystateFederalIncentivesforRenewablesandEfficiency.htm.

Glime, Sally. NWTC Coordinator for Niagara Campus. Information on hot water

usage for Niagara Campus. November 27, 2007. Harper, Gavin D.J. Solar Energy Projects for the Evil Genius. New York: McGraw

Hill, 2007. Schaeffer, John. Real Goods Solar Living Source Book. British Columbia, Canada:

New Society Publishers, 2008. Schlager, Neil, and Jayne Weisblatt. Alternative Energy, Volume 2. Detroit:

Thomson Gale, 2006. Sun Earth Inc.Solar hot water heating technical Bulletin Volume 3. Flat Plate

Collectors Vs Evacuated Tubes – A Briefoverview. http://www.sunearthinc.com/Evacuated%20Tubes%20V%20Flat%20Plate%20Collectors.pdf.

Tedder, Jim host. ‘Green’ Schools Grow Around Us. VOA News. 11 October 2007. 1 November 2007. http://www.voanews.com/specialenglish/2007-10-11-voa1.cfm?renderforprint=1.

United States Green Building Council. Green Schools Advocates Program. 5 October

2007. 1 November 2007. http://www.usgbc.org/News/PressReleaseDetails.aspx?ID=3393

United States Department of Energy. Office of Solar Energy Technology. Solar Hot

WaterTechnology. August 2000. November 1 2007. http://www.eren.doe.gov/solarbuildings

U.S. Department of Energy, Solar Energies Technology Program-Multi-year

Technical Plan, 2003-2007 and Beyond, January 2004. U.S. Department of Energy. Annual Energy Outlook 2006. Washington D.C. 2006.

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U.S. Department of Energy. A consumer’s Guide to Energy Efficiency and Renewable Energy. September 12, 2005. Http://www.eere.energy.gov/consumer/you_home/water_heating/index.cfm/mytopic=12910.

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Index

A

Active, 4, 5, 9, 10 Atmospheric gases, 7

B

Benefits, 4, 6, 7

C

Collector panel, 9 Collector panels, 11 Construction, 4, 6, 12

D

Direct Systems, 4, 10 Drainback, 10

E

Environmental, 4, 6, 7

F

Fossil fuels, 7

G

Greenhouse emissions, 7 Greenhouse gases, 7

H

History, 4, 6, 8 Homeland Security, 4, 7

I

Indirect Systems, 4, 10

M

Maintenance, 6, 11, 12

N

Natural gas, 7

P

Passive, 4, 5, 9, 10 Pressure relief valves, 11 Property Value, 4, 8 propylene glycol, 10

R

Renewable energy, 6, 7

S

SDHW system, 8, 10, 11 Solar, 4, 5, 6, 7, 8, 10, 13 Solar energy, 2, 6, 7, 10, 11 Storage cylinder, 9

T

Tax credit, 8 Thermosiphon, 9 Thermostat, 11 Transfer mechanism, 9