Fall 2011
Maplewood Seasons
The Greening of Maplewood Renewable Energy By Shann Finwall, Environmental Planner
Minnesota’s primary source of energy comes from fossil fuels such as natural gas, coal, and petroleum. Environmental and health problems are associated with the mining, transportation and burning of these fuels. In 2009 the typical Minnesota household consumed 100,766 kWh per year of energy, 10% more than the average American who consumes 90,265 kWh. We can reduce energy use by 28% if we aggressively implement energy efficiency programs such as adding insulation to homes and businesses, installing energy efficient windows, setting water heaters to 120 degrees F, replacing incandescent with compact fluorescent bulbs, or installing a programmable thermostat. But where do we turn once we have done all we can to be more energy efficient? Our next best option is renewable energy, or energy that comes from a source that has an endless supply. Renewable energy includes energy created by the sun (solar), energy from the wind (wind power), and energy
generated and stored in the earth (geothermal energy) to name a few. These types of energy systems are safer for the environment, and will help America reduce greenhouse gas emissions and become energy independent. But there is a price to pay for all forms of energy - large wind turbines can affect bird and bat populations, solar energy only generates when the sun is shining, and renewable energy is more expensive than nonrenewable energy. Doug Shoemaker, Vice Chair of the Minnesota Renewable Energy Society, said that Americans have been spoiled with inexpensive fossil fuel energy for so long. We base our decisions on what is the cheapest energy right now, without looking at long-term environmental and health costs. Electricity is inexpensive due in part to government subsidies for electric plants and infrastructure. Mr. Shoemaker states the reality is we need to be looking long term at energy, not just what is cheapest now. Like any new technology renewable energy technology will become less expensive over time. For now, there are energy rebates and incentives available to assist homeowners with installing renewable energy systems (refer to rebates and incentives below).
The Maplewood Environmental and Natural Resources Commission drafted an ordinance to promote renewable energy systems that have positive impacts in energy conservation. The Renewable Energy Ordinance includes regulations that will allow for wind, solar and geothermal energy systems in residential and commercial zoning districts. These regulations are proposed to balance the need to improve energy sustainability with concerns for the preservation of public health, welfare, safety, and environmental quality and aesthetic values. The City Council will review the Renewable Energy Ordinance on September 26, 2011, at 7:00PM. For more information on renewable energy and the draft ordinance, go to the City’s energy webpage at www.ci.maplewood.mn.us/energy. Resources: US Department of Energy (www.energy.gov); Environmental Law and Policy Center (www.elpc.org); American Council for an Energy Efficient Economy (www.aceee.org)
Rebates And Incentives For Renewable Energy Xcel Energy Solar Rewards www.xcelenergy.com/Save_Money_&_Energy/For_Your_Home/Renewable_Energy_Programs/Solar_Rewards_-_MN Xcel Energy - MN Bonus Solar Rebates www.xcelenergy.com/Save_Money_&_Energy/For_Your_Home/Solar_Rewards/Bonus_PV_Solar_Rebate_-_MN Xcel Energy Ground Source Heat Pump Rebates www.xcelenergy.com/Save_Money_&_Energy/For_Your_Home/Heating_&_Cooling/Ground_Source_Heat_Pump_-_MN
Xcel Energy Windsource Program www.xcelenergy.com/Save_Money_&_Energy/For_Your_Home/Renewable_Energy_Programs/Windsource_for_Residences_-_MN DSIRE – Incentives for Renewable Energy www.dsireusa.org
Energyscaping - Reduce Your Home’s Energy Use With Landscaping By Virginia Gaynor, Natural Resources Coordinator
Most homes have some passive solar heating, even if it’s just a window where the cat curls up for a winter nap in the sun. On sunny winter days, solar energy can make up as much as 5 to 20% of the energy needed to heat a home. Thoughtful planting of trees and shrubs in relation to the seasonal angle of the sun can help heat or cool your home. This type of landscaping, called energyscaping, reduces energy consumption and costs. During winter in Minnesota, the sun is low in the sky and can provide solar heat gain through south facing windows. Deciduous trees planted on the south will let the winter sun shine in, whereas evergreen trees will block this valuable solar gain. Cold winter winds entering a house can lead to increased energy use, but you can plant trees and shrubs strategically to shelter your home from winds. In summer, the sun is high in the sky and more solar energy enters windows on the east and west than on the south. Shading these windows can reduce summer cooling costs.
Deciduous trees planted on the south let in winter sunlight
Solar Works In Maplewood
Tuesday, October 11, 6:30 - 8:00PM Maplewood Nature Center Join neighbors and local businesses for a FREE solar energy workshop. You will learn solar basics, hear Planting strategies for saving energy: from people that have solar arrays on their homes or • Plant trees so they shade east and west windows in summer. businesses, and find out more about solar energy • Plant trees so they don’t shade south windows in winter. assessments, incentives, and rebates. Get assistance • Plant foundation shrubs to help reduce the winter wind from coming into the home. determining if solar is a fit for your family or business, • If your lot is large enough, plant a windbreak of trees and shrubs to block the winter and we will connect you to the technical and financial winds. These usually come from the northwest in our area, but may differ due to resources to make it happen. This workshop is terrain and structures. sponsored by the Metro Clean Energy Resource Team (CERT) in partnership with Xcel For more information on energyscaping, download the University of Minnesota publication Energy and the City of Maplewood. on energy saving landscaping at www.sustland.umn.edu/design/energysaving.html. Call 651.249.2170 for more details.
Resident Spotlight: Solar Photovoltaic System For The Home By Matt Ledvina, Maplewood Resident
The process of implementing a renewable energy system begins with conducting an audit to identify areas where simple, low-cost changes can yield large savings on your electric bill. Once we did this, we looked at specific site conditions to see if a solar photovoltaic (PV) system could be installed effectively. We assessed the solar resource and found that we had sufficient southern exposure on a portion of the roofs above the garage and house at the rear of the home.
Solar PV installed on south side of home
Fronius inverter
Maplewood Seasons 2
For the various programs, installations up to 5 kWh were allowed. We installed a 4.5 kWh system which was based on 20 solar PV panels that would comfortably fit on the roof. Details of our system are as follows: • System installed in July 2011 • There are 20, 225-watt Solon PV panels • Fronius IG4000 inverter for grid tie • 5,630 kWh generated • 3.6 tons of CO2 avoided • $560 of electricity generated • Electricity that is not used in our home • 4,500 watts (4.5 kWh) of generating capacity is sent to the grid. Excess power • The system supplies 60% of our generation is credited on our energy bill. electrical needs on average The system was installed by Powerfully Green, LLC, at a cost of $30,000. After tax credits and program rebates, the net cost of the system was approximately $3,000. The payback is estimated at approximately 4.5 years considering anticipated electrical generation rates.
Nature Center Solar Photovoltaic Project
By Ann Hutchinson, Lead Naturalist
Nature Center recently installed PV panels consisting of 8, 3’ by 4’ panels
The Maplewood Nature Center is sporting a brand new look thanks to Federal, State, and City Green initiatives! In an effort to reduce our carbon footprint, the City applied for and received a Solar Energy Legacy Grant from the Minnesota Department of Natural Resources for photovoltaic panels and solar educational components at the Nature Center. Photovoltaic (PV) cells collect the sun’s rays and transform them into useable electric power. The Nature Center PV project consists of 8, 3’ x 4’ panels, installed as an awning on the south (front) side of the building. The panels are connected by micro inverters that convert the direct current (DC) produced by the cells to alternating current (AC) that our homes and businesses use for electricity. These particular inverters also allow us to see how much energy each panel is producing. You can see this from your computer at home also! Check out the city’s website at www.ci.maplewood.mn.us/energy, or visit the Nature Center’s new solar PV exhibit. Today’s PV cells can only transform 12% to 20% of the sun’s energy to electrical energy. Current research is focused on increasing this percentage. Therefore, it is important to also reduce the amount of energy consumed. The Nature Center is doing just that with replacement of an old air conditioner and furnace with new, highefficiency appliances and the installation of high-efficiency T-8 fluorescent bulbs and ballasts. The Nature Center PV panels can produce up to 2,150 kWh of energy. During a bright sunny day that is enough energy to run 15 light fixtures per hour. To generate more energy the Nature Center would need a larger PV system mounted on top of the roof with a different tree profile. The installation of the panels as an awning unit on the front of the building allows for clear visibility and added educational value. Maplewood Seasons 3
Tapping Into The Sun’s Power By Ann Hutchinson, Lead Naturalist
This summer I stood under the filtered light of the Nature Center’s ash tree and watched Killmer Electric install the seemingly magical solar photovoltaic (PV) cells that would soon transform sunlight into electricity. I also thought of the amazing ability of leaves to tap into the power of the sun. As we all know, leaving a plant in the dark for weeks will surely kill it. And without plants, we would be without some of the basic elements necessary for living, such as oxygen for breathing and tasty edibles like juicy tomatoes and sweet corn!! So I mused, how much is a leaf like a solar cell?
Green leaves transform sunlight to food
Both leaves and PV cells capture sunlight and use it to transform energy. But leaves use photons (particles of sunlight) to transform sunlight, along with water and air, into the food they need to live. Deep inside a leaf’s cells, microscopic chloroplasts work like tiny food factories. There the photons (particles of sunlight) strike a green pigment called chlorophyll and begin the chemical process called photosynthesis that produces glucose or sugar. Without this process plants wouldn’t grow and animals wouldn’t have anything to eat! PV cells, unlike leaves, transform photons into electricity. First invented in the 1950’s, they have no moving parts, and run silently. PV cells are made from silicon, the most common element in the earth’s crust. There are two layers of silicon, one with too many electrons (negatively charged layer) and one with too few (positively charged layer). When sunlight hits the negative layer, it knocks electrons loose. As they flow toward the layer with too few electrons an electrical current is created. A wire is placed in the cells and the electrons flow along the wire, thus directing the flow of the current.
Sunlight helps plants produce food
As Thomas Edison once said “Someday we will harness the rise and fall of the tides and imprison the rays of the sun!” The amount of energy from sunlight reaching the earth in one hour is greater than the amount of energy used by every person on the planet in an entire year! Solar PV cells are allowing us to tap into the sun’s power, just as leaves do. As the technology advances, we will be able to imprison all of the rays of the sun! Reference: Teaching Solar edited by Clay Atchison, Rahus Institute: www.californiasolarcenter.org/index.html
Materials: Large Pizza Box Utility knife (with grown-up help) Plastic wrap Tape* Aluminum foil Black paper Plate* Chips and shredded cheese
By Oakley Biesanz, Naturalist
* do not use materials that could give off toxic fumes when heated such as duct tape or styrofoam
pizza box.
4. Tape plastic wrap on
top of cover to seal in heat.
2. Cut out a large “reflector” flap from the cover.
7. Place chips with
shredded cheese on a plate, place in the bottom of the oven & close lid.
9. Wait between 10– 40
minutes for cheese to melt depending on the sun conditions. (caution- hot!)
3. Cover the
inside of this 5. Cover inside flap with bottom of box with aluminum foil aluminum foil.
(shiny-side-out)
6. Place black paper on inside bottom of box.
8. Lift the reflector flap
& prop it with a stick. Place oven in direct sunlight– facing toward sun.
10. Eat! Enjoy plain or
with salsa & sour cream. Maplewood Seasons 4
Printed on 50% post-consumer paper
Solar Oven
We have free solar energy all around us. On the next sunny day, see if you can tap into the sun’s energy to cook up some SUN-licious nachos! 1. Get a large
Check out the Nature Center’s solar cooling hat