Solar Panels on Frosty Morning

An interesting thing regarding solar panels is their configuration or setup. Our 525 panel array is configured so that several panels are connected in series as a "string", and then combined with other strings to send their DC current to an inverter where the output becomes AC current.

One design challenge is that the panels in that string need to be working well together. If 3 out of 7 panels in a string are not functioning - the entire string is unable to make production. On Nov1, we had an exceptionally clear and cold day. The panels had a frost that settled on them, and with the early morning sun rising clearly and slowly, the melt of the frost followed the shadow line as the sun rose in the sky. As you can see by the above photo, that meant that some panels, though being struck by sunlight, were unable to pass along their energy generation because other panels in the string were not producing energy due to frost blocking the light.

One solution to this is micro-inverters that would convert the DC current on each individual panel into AC current. It is an interesting concept, which this NYTimes article discusses more.

The photo is from 8:30am, and the array kept going in and out of operation as the sun glinted just enough light and energy on the threshold of operating. During the day total, there were 452kwh generated, the most in nearly a month.

As of Nov1, the array has generated all electrical needs for the company, even with us switching gas heaters to electric and adding an electric car that charges it's battery here. In fact, the array generated all the needs, and created excess of over 14,000 kwh. The credit of kwh generated and pushed to the grid beyond our consumption pulled from the grid, will be drawn down upon during the winter months when we do pull more than is pushed to the grid.

Hot Water Heater - Electric vs Gas

The hot water heater in the manufacturing area serviced wash basins and a bathroom. It was gas fired, 50 gallons, and needed replacement. We switched to a 6 gallon electric which we believe will yield substantial savings.

A physical review revealed that use of hot water occurred only at end of work periods (break-time, lunch, end of day). Otherwise, the system was maintaining 50 gallons of hot water during off periods (such as evenings and weekends).

An on-demand system would not work due to the heavy load that occurs upon lunch time as an example, when all the workers are using actively washing up before a meal.

A 6 gallon tank was found to be the right size for our peak use. The tank takes up less room, and doesn't require the venting like the former natural gas fired tank.

The comparison of costs and determining payback of investment is offered via this government website.

The system has been in place for 2 months, and functions as projected. We have ample electricity surplus from our PV solar array, so we have eliminated a natural gas purchase for the energy, as well as have eliminated the pollutants from burning the gas. All hot water in our facility comes from electric heaters, with electricity gathered from our Photo-voltaic array of panels.

Electric Vehicle Delivery Truck

Electric delivery vehicles are a possibility of the future, which is why we are currently testing the feasibility via the electric passenger vehicle (the only pure EV available is the Tesla Roadster).

Our typical market served requires a 150mile round-trip capability. Currently the trucks being tested or shown in auto-shows have a 100mile range (and that is not descriptive of the load they may carry).

This link provides a glimpse at what may be to come for larger vehicles, and this link shows that smaller delivery vehicles powered by electricity (solely) are becoming available (to fleet owners).

Images drawn from and copyright autoblog.com

Emergency Preparedness

The location of our operation in Derby, CT has had quite a history. It was a cannon factory, then a munitions factory, and just previous to our residence, a dye and print factory of fabrics. There was a fire at the location in the mid 1980's that devastated the property. You can see the canal alongside the property from which previous occupants tapped it's kinetic energy for powering machinery. In recent years, it powered a turbine to generate electricity for McCallum Enterprises, who have a similar facility on the Shelton side of the Housatonic River.

Given that emergency personnel in Derby (ambulance and fire) are volunteers, it's important that they be aware of our operation's layout and the hazards to be aware of within. When responding, seconds can make quite a difference and rather than require someone to call up drawings and files and radio them to the responders, we thought - why not make it available to them via the internet?

We created the most simple of webpages: ida-intl.com/911.htm

This should be accessible from most smart phones or a laptop that has internet access. The page contains only text so it's easily readable, but contains:

• instruction on where utilities access the property
• emergency contacts of property owners
• basics on the construction materials and layout of the structures on the site
• chemicals that are typically stored and their location on the property

We even created a QR (Quick Response) code posted on signs at our location for those who have such software on their phone. Snap a photo, and go direct to the webpage with the data.

Electric Vehicle Public Charging Station

Just this month, we installed a weather proof outlet to charge our Tesla electric vehicle at our Derby location to harness the "free" solar electricity rather than power a car by hydro-carbon fuel.

As early adopters to such means of transports, the challenge for electric vehicle drivers is finding places to charge up quickly. After we installed our equipment, we thought: why not offer free charging to other electric vehicle owners? One hour of charging on our 220v 40a outlet would only cost us about 40 cents. If someone were to spend an hour charging their vehicle, it would put another 25 miles in their "tank", and while they waited they could enjoy some food and bring business to our favorite pizza joint across the street, Apollo Pizza (tell Gus we sent you).

We put together a webpage describing our charging location and what we offered, and made mention of it on the forum pages of the Tesla owners website. To my knowledge, IDA International is offering the first free public charging location for electric cars that is powered from the sun in the State of Connecticut - maybe the USA?

It didn't take long!! On 2010/Sep/20 we had our first visitor with Mike from New Jersey! On his way toward home from Massachusetts, he stopped for a quick top-off while he toured our factory where we explained how the solar array functioned that was currently filling his car with energy.

Visit our Derby location and we will offer you free electricity for your car that we've gathered from the sun. And you might enjoy a good pizza!!

Electric Vehicle Charging

If you read this blog, you will know that the company's operation in Derby, CT has a solar array that provides all our electricity needs, and then some (114% of our consumption since the installation went live in 2009Mar).

Rather than sell that electricity to the utility (in March the electric company sweeps out any kwh we have "banked" and pays us based on the average rate of the New England Regional market, which is about 5cents per kwh), the value is in deferring buying electricity from the utility (which in total of all the line items on your electric bill is about 21cents per kwh).

As mentioned earlier, we have a diesel powered delivery fleet of light-duty trucks. With a round-trip delivery of apx 150 miles, they might one day be served by electric power. We are testing the viability of this with the only pure electric vehicle available to non-fleet owners as a purchased vehicle, the Tesla Roadster. While not a "delivery" vehicle, it is a real-world case study in how electric vehicles perform in hot or cold weather, and the reality of their charge time that yields miles driven. Our methods and purpose is not unlike Google's fleet of vehicles.

An issue often raised is that there needs to be a charging station infrastructure for people to adopt to such vehicles over internal combustion engine power. While there are outlets most everywhere (the Tesla can charge on 110v 15a), a quick charge requires power and that comes in 220v 40a or higher.

The defining characteristic is power (kilowatts) input into the batteries. Returning to your basic science: Watts = Volts x Amps. Thus, 110v x 15a = 1650w, or 1.65kw. Plug in for an hour and you have 1.65kwh. Go with a 220v x 40a for an hour and it = 8.8kwh, which equates to substantially more miles from the contribution to the battery's storage of power.

To put this in real world terms from our actual experience and data, charging a Tesla for 1hr at 110v = 5 miles of driving. 1hr at 220v = 25 miles of driving.

Vehicle efficiency

Our fleet of vehicles is primarily for delivery of finished product. Given that there is little storage on construction sites in Manhattan, our deliveries are almost daily for the material that will be installed promptly. The weight and size of materials being delivered results in diesel powered trucks proving to be the best vehicle choice.

Looking to the future, there is a possibility that delivery vehicles could be electric. To test this concept, a real-world case study is underway. There are very few plug-in electric vehicles available unless you participate as part of a large fleet. At the current time, the only plug-in electric vehicle readily available is the Tesla Roadster.

Having driven one from home to work this morning, it took 788 watt hours of energy. This is the same energy as a 60 watt light bulb left on for 13hrs and 8minutes. At peak generation time of our solar array, that much energy is captured from the sun in 28.4 seconds. If purchased from the electric utility, it would have cost 17 cents.

This alternative vehicle does have limitations due to the charging time nature of the batteries storing energy, so more testing of the concept is required.