Our blog post this month is an article that appeared in the October 4, 2017 Bennington Banner describing how we worked with Green Mountain Power on an installation at Emerald Lake State Park to get the park off the grid. Thanks to The Bennington Banner for allowing us to reprint it here. [Read more…]
Clean power is well and good, but how clean is it?
Renewable energy sometimes comes under attack. How often have you heard someone say:
• Don’t they use toxic chemicals and heavy metals to manufacture solar panels?
• You can’t recycle panels.
• I hear manufacture of solar requires lots of fossil fuel energy.
• I hear solar power uses a huge amount of water in manufacturing.
We are going to address all of these misconceptions and give you the facts about solar sustainability.
The Silicon Valley Toxics Coalition reports a thorough scorecard every year for solar manufacturers. Some of the materials they are concerned about include:
In 2008 a Washington Post reporter found suppliers of silicon dumping silicon tetrachloride, a toxic byproduct, onto farmland in China causing health and environmental hazards. This byproduct can actually be captured and used to create more silicon in a process that requires less energy than extracting it raw but the equipment involved is very expensive. Suppliers cutting corners led to toxic dumping. Now, leading solar companies like SunPower require their suppliers to retain and reuse silicon tetrachloride for silicon production. An additional article is here.
Thin-film panels which are essentially printed on glass, are made with cadmium and require special disposal methods. SunPower cells are made with no heavy metals and do not require hazardous waste disposal.
That brings us to…
Want to know if there’s a take-back program at the panel ‘s end-of-life? YES! SunPower panels have a life of up to 40 years, and the company is leading the industry effort to launch the first US national recycling program. SunPower covers the cost of end of life disposal of all their product.
Manufacturing and Shipping:
The source of electricity to manufacture solar cells is another potential problem: if the electricity is largely from coal-fired plants, the panels have a larger carbon footprint.
So, in China where electricity is primarily coal-fired, the carbon pollution is double that of panels produced in the US or Europe. Add in the pollution of transcontinental shipping, and it takes twice as long for the clean energy produced to offset the greenhouse gases emitted in making the panel.
Water to cool and operate fossil fuel and nuclear power plants is much greater than that used for solar production. Most water waste comes from washing dust off panel surfaces, which can be reused as greywater for vegetation.
SunPower panels led the SVTC Solar Scorecard for 2015 with a 97 of 100, rated for manufacturing practices, labor conditions, environmental standards for products, safety of materials, and company recycling of products.
SunPower’s factory in Mexico meets Cradle-to-Cradle Silver Certification, adhering to stringent standards of sustainability for materials, safety, energy and water use, and worker conditions as well as recycling for all materials. SunPower’s manufacturing plant is also third-party verified as landfill-free; each achievement is a first for the industry. SunPower products are designed for peace of mind at every step of the way. (6 )
Sustainability is important to you. It’s important to us at Grassroots Solar, and that is why we think that our customers should Demand Better Solar.
Energy Terms Explained
We bandy about a lot of technical words when discussing electricity, and it’s helpful to know some basic terms. Electricity is essentially the flow or movement of electrons, so it can help to picture electricity in a wire like water in a garden hose. The water pressure in the hose is similar to voltage (in volts, V) and the current (in amps, A) is like the width of the hose, representing the volume of electricity moving through the wire. If the hose is not very big, it takes a long time to fill a watering can.
A wire needs both voltage and current to produce power, like a hose that needs pressure and a volume of water flowing through it in order to spray water. If either voltage or current is at zero, no electricity is produced, just like no water comes out of the hose if it has no pressure (when the tap is turned off), or no water volume (when the hose is empty). Electric power (in watts, w) is the ability to do work with electricity, and in this example electric power is like the ability to spray water with the garden hose. Power = Voltage x Current
We measure electric power in watts (w) or kilowatts (kW) (kilo equals one thousand, so 1000 watts = 1 kilowatt). Electric power (w) is required to turn an appliance on.
If you have ten 100 watt light bulbs* in your house your demand is 1 kilowatt of power to turn them all on at once. When you leave your lights on for a period of time, you use energy, which is power use over time, so the unit is in kilowatt-hours (kWh). If you keep all the lights on for one hour, you have just used 1 kilowatt-hour of energy. In our hose analogy, electric energy would be compared to the amount of water you sprayed on your garden in total, over the course of time.
The utility charges you for energy—how many kilowatt-hours you used this month. Total kWh will show up as a line item on your bill, multiplied by your electric rate. If you have a business and turn on all of your machinery at once the utility might also charge you for demand in kilowatts, because it costs them money to meet that demand when you suddenly use a lot of power. Demand charges will be billed by the number of kW used in a 15-minute window.
The electric meter that measures your electric usage in kilowatt hours (kWh) is similar to the water meter that measures your water usage in gallons per hour. So when you pay your electric bill, you are paying for kilowatt-hours of energy. And when the sun is out and your solar array is producing power, you are selling it to the utility in the form of kilowatt-hours of energy.
A single 3-foot by 5-foot SunPower module can produce 360 watts of power when there is sun shining on it. If the sun shines on it for 1 hour, that panel produces 360 watt-hours of energy. If the sun shines on it for 4 hours, the panel produces 1,440 watt-hours, the same as saying 1.44 kilowatt-hours.
Power is in kilowatts (kW)
Power (kW) x Time(h) = Energy (kilowatt-hours kWh)
A 5kW solar array produces approximately 6,250 kWh in energy over the course of a year**, and now you know the difference.
*Note that this example uses old inefficient incandescent light bulbs, if you have any left, you should replace them with LED light bulbs that are as bright as a 100w and almost ten times more efficient.
**This can be better or worse depending on weather, shading, direction of the roof, a lot of factors can change production.
Sales & Site Design
Who’s Really Killing Coal?
We’ve heard a lot about the Trump administration’s plans to bring back jobs in the coal industry by removing EPA regulation. While the executive orders are already rolled back and the Clean Power Plan comes under the chopping block, it turns out market forces, not EPA regulations, are the driving cause of coal’s impending demise. If supporting American energy production and creating jobs were truly priorities for this administration, they would support the burgeoning renewable generation industry.
How did we get to this present state?
Let’s examine the market forces at work behind coal’s dry spell, and note that these forces will not go away with the removal of regulations. First, coal jobs are less plentiful due to the rise of automation that started in the 80s. The process of extraction is now simply become more efficient which equals fewer jobs. Second, in West Virginia where people are most impacted by loss of coal jobs, wide and easily accessible seams of coal are now exhausted. Mountaintop removal requires greater investments and high technology to extract new coal, but not greater manpower. Third, natural gas has become cheaper than coal in the U.S. And as it pollutes less heavily than coal, it is replacing coal much quicker than anticipated, acting in its intended role as a “bridge fuel” to curb the worst carbon emissions from coal. (It’s worth noting that natural gas still creates methane leaks- difficult to detect and 20 times more potent a greenhouse gas than carbon dioxide!) Combine those factors with the fourth, global pressure on energy investors to buy and build new generation that reduces emissions, and coal’s once limitless investment pool is drying up as it becomes more expensive to extract. Coal will continue to decline in prominence due to market forces alone, though it will be dirtier than ever without EPA regulations.
The good news is that coal’s days are numbered.
The markets for renewable energy are taking off, with renewables coming to a competitive price point far more quickly than predicted, and in some places are already cheaper than natural gas. Solar and wind already employ more people nationwide than all types of fossil fuel energy production at the utility scale production level, according to the DOE’s Energy and Employment Report for 2017. In fact, jobs in solar generation are growing 12 times faster than the economy average, while jobs in fossil fuels are stalling. Let’s step back and think about that for a second. In 2016 solar electric generation created more new jobs than oil, gas and coal combined, and that’s just at the utility scale. If we included all the regional installers of distributed generation for residential and smaller commercial systems, like Grassroots Solar, we would see even more astonishing figures.
A forward-thinking business person looking at the numbers would clearly see the rising future of job creation and market opportunity that renewable generation represents, and recognize a chance to do well by doing good. Every year global solar energy production doubles as more arrays are installed in what we call exponential growth—growth that looks modest for the first few years and then skyrockets. Supporting America’s clean and independent energy sector is the best way for the administration to meet their stated promises in job creation, rather than removing support to this industry in favor of even more subsidies and freebies to fossil fuel. Soon or later, our governing bodies will recognize the grassroots movement to demand and create domestic renewable energy generation and we here at Grassroots Solar are happy to be part of that movement.
In the rich farmland valley of Pawlet, there is a classic 1850’s Vermont farmhouse with Greek Revival bones, complete with a silo and a collection of outbuildings-quintessential Vermont to its core. Alongside ‘the old chicken barn’-something new has sprouted…..solar panels. The farm has a long history, which got us wondering at Grassroots Solar about the why’s of adding solar to this farm scene, and so I sat down for coffee with the owner, Barb Moore, at Dorset Rising café one winter morning to find out what inspired the change.
The story begins in the Vermont of the 1940’s. Barb’s father returned from World War II and took advantage of a training program for veterans in agriculture at Green Mountain College. He started out as a dairy farmer but then converted the longest barn on the Pawlet property to egg production and sold fresh eggs to the community until 1988. After he passed, the farm lay idle for a while. Barb “always had a dream to transition the fields over to organic farming but there were several failed attempts at it over the years.” Nothing seemed to fit until a young couple, Tim and Brooke, approached Barb to use the land for growing organic sweet potatoes. Now, in its fourth year, Laughing Child Farm has become the largest organic sweet potato grower in Vermont!
I asked Barb what made her consider adding solar to the farm. Very quickly she replied, “I had trust in the solar provider.” Well, since we can take a compliment, with a shade of humility, we accepted that reason. You see, Bill and I go way back with this client – I decorated Barb’s farmhouse and Bill made custom furniture for her in our previous careers. So, there was a level of trust that had deep roots.
I wondered what her forefathers and mothers would have thought about solar panels on their farm and she said “They would have been intrigued by them and they were always looking for what was new and helpful to the production of the farm.” That makes sense. These were practical folks after all. Anything that saved them money and made them more resilient would have gone over well.
Barb sees parallels between solar and the local food movement. “Both keep local control and build community and I see young people embracing sustainability in all ways.” She has deep ties to the local food movement as the owner of The Good Table, a catering business that using local and organic food, so she thinks about this often.
The solar panels add a contemporary element to the farmscape and I wondered what Barb thought of the aesthetics of the 2 pole mounted arrays. Pushing back a bit in her chair, she said, “I am surprised at the small footprint and how they don’t seem obtrusive, but blend nicely with the outbuilding and fields.” I mentioned to Barb that sometimes people add a layer to the solar array by planting a pollinator garden around the poles. Pollinator gardens consist of flowering plants that sustain bees and insect pollinators with food and shelter. Well, that got us thinking and by the last sip of coffee we were already scheming to put together a Pollinator Workshop for our local environmental group, Transition Town Manchester, to teach ourselves and our community how to go about creating something beautiful and useful for our ever evolving Vermont landscape.
Stay tuned for the upcoming workshop date this spring.