Tag Archives: SunStation

Renewable Home Power, Backup, Heat and Air Conditioning

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Princeton Satellite Systems has been in a leader in renewable energy with its SunStation home solar power system with battery backup. We introduced this product back in 2013. SunStation has lithium-ion phosphate batteries, the most stable and reliable batteries for home use. The core of the system is the Outback Inverter that seamlessly switches from grid power to internal power.

The solar system in the installation produces 7.3 kW of power, much more than the house needed for electric power including charging a Nissan Leaf and Toyota Prius Prime. The heating and air conditioning system was nearing its end-of-life so we decided to replace it with a geothermal heat pump. A heat pump is essentially an air conditioner that can both reject heat to a source and absorb heat from a source. The problem with both is that when the outside temperature is high, for rejecting heat, and low, for absorbing heat, the system loses efficiency. Modern air-source heat pumps are very efficient but do need backup resistance heating in some climates.

A ground source heat pump, or geothermal heat pump, uses the ground as the medium for absorbing or rejecting heat. The option we chose, due to land constraints, is to have two wells several hundred feet deep as the source. Alternatives are trenching, or a pond if you have one in your yard. The ground is always at around 50 deg F. The system was sized so that it rarely, if ever, needs resistance heating.

The geothermal system, which is made by WaterFurnace, was installed by Princeton Air. No changes to the SunStation were needed. The core geothermal system is shown below. The valves to the ground loops are in the foreground and the geothermal system is on the left.

The lines that run to the outside ground loops are shown below.

The system has a preheater for the (still gas) hot water heater. The gas water heater was less than a year old, so it didn’t make sense to replace it. The preheater is an electric hot water heater that does not have the heating coils connected.

The SunStation is shown below. The Outback inverter is on the bottom left. The boxes on top provide arc protection, which is now included in the inverter. The batteries on on the right and the battery management electronics between the inverter and the battery cabinet.

The well digging was quite a project. This picture shows the drilling rig.

This second picture shows the yard after the drilling was complete. Drilling took three days total.

The following system shows the SunStation with geothermal in operation. The Prius Prime is charging which is most of the load. The system is still sending considerable power to the grid. On average the house powers itself and two other houses.

Geothermal, with solar and battery backup is the ideal solution for new homes and for renovations to existing homes. There is no reason to even have a gas hookup anymore. Contact us at SunStation for more information

SunStation in October

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The following image shows SunStation in operation on a bright October day! The load for the day was 12.4 kWh. This includes charging a Nissan Leaf and a Toyota Prius Plugin-in. The total power generated was 40.3 kWh and 21.4 kWh was sold to the grid. As you can see, the installation is much more than carbon neutral with regard to electrical power. It has a gas heating system so is not completely carbon neutral.

OPTICSRE

The orange line is the state of charge for the batteries. The 14.4 kWh of batteries is enough to keep the home running, charge the Prius fully and the Leaf partially, when the grid is down. The system automatically disconnects itself from the grid when there is an outage.

The house itself is fairly energy efficient with mostly LED lights and a few CFLs. The heating system is high efficiency with a 60 W fan that operates most of the time. The house is air-tight and has a whole house air exchange system that operates continuously. The refrigerator is 10 years old and the washer and dryer are less than 10 years old. As you can see, the typical load is 500 W except when the cars are charging. The efficiency could be further improved by installing a state-of-the-art central air system and replacing the refrigerator.

The Nissan Leaf is 100% electric. On a normal day the Prius operates on battery stored energy about 80% of the time. It visits the gas station once every 3 weeks or so.

Besides saving money on power, the system produces 7 Solar Renewable Energy Credits (SRECs) yearly. At current SREC prices, that is about $1500 a year in revenue. The homeowners own the system so all the revenue goes directly to them.

SunStation in Operation!

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SunStation is in operation! The system produces a peak of 7.8 kW solar power. It has 14 kWh of lithium batteries. The SunStation electronics are shown below. The inverter is on the left. The batteries are in the cabinet on the right.

SunStation

The SunStation has a web interface. You can see that when this screen shot was made the SunStation was selling 5.1 kW back to the power company! The batteries are fully charged. Usage was very small. The house has a whole house ventilator that is drawing most of the power. The homeowners also own a Nissan Leaf and a Toyota Prius Plugin. The solar array is enough to fully recharge those cars and run the house electrical devices when the air conditioning is not on.

SunStationWebInterface

Unlike gasoline, diesel or natural gas systems SunStation provides power year round! There is no noise and no toxic emissions. SunStation has no moving parts and is zero maintenance. Solar power systems are eligible for Solar Renewable Energy Credits which are cash payments for having an operating solar power system. It is estimated that this system will bring in $3700/year revenue between selling power and SRECs.

SunStation Installed!

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The first SunStation installation is done! This system includes 14 kWh of Valence lithium batteries and an Outback inverter. Unlike most other solar power systems, the solar panels will deliver power to the house with or without the grid active.

SunStationInstalled

An existing 3.8 kW array was augmented with the new Panasonic solar panels on the right. They are about the same size as the older Sharp panels but much more efficient. In the bottom picture you can see the Outback inverter. The cabinet on the lower right houses the Valence batteries. The system will power the entire house in an outage with the exception of the central air conditioning system.

Unlike gasoline, diesel or natural gas systems this system provides power year round! There is no noise and no toxic emissions. SunStation has no moving parts and is zero maintenance. Solar power systems are eligible for Solar Renewable Energy Credits too which are cash payments for having an operating solar power system so you save money two ways.

Check out our SunStation page for more information!

PSS at Princeton Plasma Physics Lab Open House

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On Saturday April 1, PSS participated in the Princeton Plasma Physics Lab Open House to show case our Direct Fusion Drive and our conceptual nine-month manned space mission to Mars in 2024! Our new fusion engine enables shorter transfer times and total mission durations, critical for interplanetary manned space flight. We had great interest in our human mission and many budding astronauts were ready to sign up for the trip.

PPPLOpenHouse2013

Please see our educational page for some fun DFD material for your space enthusiast:

http://test.psatellite.com/research/education.php

More information on this exciting project is available on our Fusion webpage:

http://test.psatellite.com/research/fusion.php

Our SunStation products for Home Back-Up and EV Charging were also on display at the PPPL Open House. SunStation is a green way to provide emergency power to critical loads in your home during an electrical service interruption or to charge your electric vehicle without using any grid power!

 

Princeton Plasma Physics Laboratory Open House

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Please join us at the Princeton Plasma Physics Laboratory from 9 am to 4 pm  on June 1, 2013.

http://www.pppl.gov/openhouse

We will have exhibits on our Direct Fusion Drive, a collaborative project with PPPL to develop a nuclear fusion rocket engine for space propulsion, and on our SunStations for home electrical power backup and electric vehicle charging.