Off-Grid Vacation Lights – The Hudson-Athens Lighthouse
The Hudson Athens Lighthouse in New York State first started operating in 1874. It served as a guide for ships sailing the busy lanes of Hudson and Athens in the late 19th century and helped them avoid the Middle Ground Flats that separate the two cities. The lighthouse was occupied from the beginning until 1950 and during that time it housed six different animal keepers and their families. The lighthouse was automated in 1949 and its beacon is still owned and maintained by the US Coast Guard. The Coast Guard was in charge of the entire property until 1984 when New York Governor Nelson Rockefeller recommended that the property be rented to a nonprofit group that would maintain the property for the public’s benefit.
With this in mind, a group of citizens in neighboring countries founded the Hudson-Athens Lighthouse Preservation Society (HALPS). This non-profit organization would take care of the physical maintenance of the property and be committed to protecting and promoting its historical value. After HALPS leased the property from the US Coast Guard for 16 years, HALPS was granted the deed for the lighthouse in 2000, making it the sole owner of the property. To learn more about the history of the Hudson-Athens Lighthouse, its light keepers and the surrounding area, visit their website: http://www.hudsonathenslighthouse.org/.
An ornate lighthouse
The company not only makes the lighthouse and its history accessible to the public, but has also delighted residents of the surrounding counties for more than 20 years by decorating the property with Christmas lights every winter season. Unfortunately, in September of this year, the underwater cable that had supplied power to the lighthouse was not working properly. Fortunately, the navigation light in the tower was not affected, as the coast guard had installed a PV system years ago to supply it with electricity. To power the rest of the house and finish their summer tour schedule, the HALPS volunteers worked with a local electrician to set up a generator. With a stopgap, they began to view solar power as a long-term solution. With the help of the Hudson Power Boat Association, they began developing a new off-grid solar power system.
altE worked with Joe Kenneally, senior volunteer at the Hudson-Athens Lighthouse Preservation Society, and Peter Rowland, a local electrical engineer, to develop a system that would ensure the Christmas lights stay on throughout winter. One key caveat: each winter, all of their docks pull ashore to protect them from ice damage, and the Coast Guard breaks ice in the canal so river traffic can safely reach Albany. Starting a boat on an ice shelf is very dangerous and it is impossible to cross. T.Society knew they only had a few months or maybe weeks to install the off-grid solar system before losing access to the site. Joe, Peter, and their volunteers set out to rescue a holiday tradition.
Design the system
A few quick calculations showed that the maximum daily load of the Christmas lights is around 1250 Wh and that by mounting PV modules on the side of the lighthouse, around 3 hours of sunshine per day can be achieved. We ended up using a 3 panel array Serokim 375W monocrystalline modules. While this is slightly oversized for the expected load, hopefully this will give society room for expansion and ensure that after a few days without sun there is enough solar to recharge the batteries (an important consideration with off-grid solar power).
The volunteers developed their own shelving system that could be mounted on the fence so that they could adjust the panels to the desired incline and thus optimize the system for winter production.
The panels were wired in parallel using a Midnite PV3 combination box. There are two advantages to this decision: First, it was possible to use a charge regulator with a slightly lower voltage (Victron Smart Solar 100 V 50 A regulator), which kept the total cost of the the system off. Second, the parallel cabling helps to mitigate the negative effects of partial shading. That is, if one panel is shaded, the output of the other two modules will not be affected.
Since the system would not be monitored throughout the winter, it seemed important to put in place certain protective measures that would prevent the batteries from over-discharging and significantly shorten their overall life. Hence another Victron product that is called Smart Battery Protect was Installed in-line between the batteries and the inverter to prevent the batteries from ever being drawn below an unsafe level. Although it For the HALPS volunteers, it was important that the lights stay on all winter and that protecting the battery bank is a priority. As a result, the Battery Protect disconnects the inverter from the batteries if it is left without the sun for a long time, thus preventing the voltage from decreasing any further – until the panels have the opportunity to recharge the batteries to a safe level. Without this additional protection, several cloudy days could possibly reduce the battery voltage to such an extent that the charge controller can no longer be switched on. This means that the system will not work until someone accesses the lighthouse to recharge the batteries with an alternative charging source. Needless to say, this would be problematic for any off-grid remote system.
For the batteries, the volunteers took advantage of the long service life and wide operating temperature range of the Outback 200 nano carbon batteries. With a bank of 4 batteries, they achieved a total of 356 Ah at 24V, which means an estimated autonomy of 2 days at 50% depth of discharge given their expected daily load.
The entire DC cabling was done in the Midnite Mini DC separation box, in which the charge controller and the inverter switch were located. This kept the system cabling clean and compact. Ultimately, we decided on the inverter The 600 W 24 V Samlex PST Pure sine wave inverter was intended for this order. By using an inverter that is just big enough to handle the maximum continuous current carrying capacity of the lights, the ghost load during the day has been reduced. This makes for a more efficient system.
HALPS lead volunteer and 35-year-old member Joe Kenneally wrote of the installation:
Six men went to the lighthouse on Saturday morning, where we had been traveling the week before to deliver supplies for building a solar system. Eight hours later, six tired, hungry men returned happy, knowing that the tradition of Christmas lights continues on the river.
The system was installed and commissioned on November 22nd, just in time to turn on the lights for the holiday season, as has been a tradition for two decades. As winter was fast approaching and the new solar system could not be serviced in the off-season, the volunteers decided to install a little fewer lights than in previous years. Even so, Joe is confident that the lights will be “as bright as ever” again next year!
Overcome time constraintss, budget constraints, and other obstacles, society has kept the local holiday tradition alive for Columbia and Greene counties – all thanks to a few dedicated volunteers, lots of technical know-how, and a little help from the sun!
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Nate is a technical sales representative at altE and has been with the company since June 2018. He is passionate about renewable energy and takes pride in developing solar systems that people can use to reduce their energy consumption and costs. Outside of work, Nate can go skiing, hiking, or fuel his coffee addiction.