Introduction: Mini Power Station. Running the Front Yard on 100% Solar Power
My tiny cottage has no power or water to the front yard. Since the home is a rental, the landlords removed the outside hose connections because tenants have rarely used them over the years and are tired of the connections freezing during winter needing repair. To upgrade and decorate my yard i needed to solve the issue of how to water my plants, and how to run outdoor lighting without the need of an extension cord running into the house.
This project also doubles as an emergency backup power rig for the house when we lose city power. It will be capable of running my outdoor lighting, limited indoor lighting, modem and router for internet, and charge my devices for a few hours while the power is out.
Power inverter: Try to find one that has an on/off switch or ease of use. Im using a combo inverter/bike pump/jumpstarter. a regular inverter will be smaller and able to fit in a more compact container.
Weatherproof container: Im using an Igloo cooler with wheels. this makes it a bit more portable
circuit breakers or fuses (i use 10amp for pump and 30amp for the inverter pack)
Wire and connectors.
Solar panel: using my trusty 10w panel with controller
Battery: I'm using an almost new car battery because the car died. If you want a cheap car battery look into recyclers, rebuilders, or junkyards. Place in my town will sell a reconditioned car battery with a 6 month warranty for $30.
Step 1: The Inverter
The inverter I'm using was a combination Jump starter, inverter, USB charger, air pump, bike pump. A nice unit, but the internal battery just doesn't have the storage capacity to do what i want/need it to do.
I removed the battery and the jumper cable leads from the unit. The jumper cable leads are reconfigured to attach to the positive and negative terminals of the battery connection. This can be wired up with a more permanent connection, but i like the long cables and the ability to use this on just about any 12v battery. The unit can also be placed on the ground next to my bike so i can use the bike pump feature to fill my tires.
On the positive terminal i added a power cutoff switch and a circuit breaker for safety. Add the breaker to the end of the positive terminal, close to the battery insures that if there is an electrical fault anywhere on that system the breaker can cut power.
Step 2: The Pump Unit
This is a previous project from my YouTube channel. This unit can be used for multiple purposes like a camp shower, to wash the car, or water my plants. I recently upgraded this to pull water from our 1/4in swamp cooler line to fill the bucket. Using a float valve, this will fill up with water and shut off when full. This solves the water problem, i now have the ability to water my plants.
The bucket will pump about 5 gallons of water in under in about 3 minutes.
Using a LED light remote control, the unit is in a semi permanent spot on my side yard and i use the remote to turn the water on and off.
Step 3: Wiring
connecting everything together is relatively simple. The inverter box and the pump control have separate breakers. If you cannot find breakers, use an automotive fuseable link with the proper rated fuse for the application. The solar panel controller box is on the back of the panel and the wiring connects to the battery with alligator clips. This allows me to move the power box or panel easily and makes it easy to pack up to take camping.
Wiring this up takes very little skill. plus to plus, minus to minus.
Step 4: Weatherproofing, Freezeproofing, and Storage.
The weather can get wild here. From 105F highs in the summer to single digit temperatures in the winter with snow. I chose this Igloo cooler (around $40 at Costco) because it should provide the some thermal protection from extreme changes in weather, keep water and snow out, and it has wheels and a handle so i can easily roll the unit around when the pump and panel are disconnected. Keeping the power station on my porch and up against the house helps provide a little extra warmth in the winter to prevent the battery from freezing.
Keep the drain plug open on the cooler to help vent any gasses generated by the battery charging.
Step 5: Charging the Battery
For my use, the 10 watt solar panel is more than enough to keep the unit charged. I use the outdoor lighting for a few hours a week and run the water pump every day for around 10min to water my plants. There are various ways to keep the battery topped off.
- A bigger solar panel.
Using a 100w solar kit and the power station during a blackout would definitely keep my internet router and modem running, charge my phone, and still charge the battery a bit while the sun is out.
- Battery charger/maintainer
Since the system runs on a car battery, you can use an off the shelf car battery charger to provide supplemental power when the solar cannot keep up. I prefer a 1.5 amp battery charger/maintainer for 3 specific reasons.
1. The battery charger/maintainer is small and could be permanently connected to the power station.
2. The power inverter in my car can power a low amp battery charger. If I'm camping i can give the battery a little charge every time i run the engine.
3. If i have a big garden party and need to run lots of lighting, the charger can provide continuous power to keep the battery topped up.
- Alternative power projects
You could add extra power with solar, wind, hydro, etc to the power station. Be creative. If i need to generate a lot of 12v power quickly, i use the 12v generator built with an old briggs engine and an alternator from an old truck (see video).
Step 6: Using the Power Station and Knowing the Limits.
After you find a good place to store the station, set up your charging solution, and have it ready for use, see what the limits of the storage capacity are to know how much power you have in reserve. Find out how long the station will run all the equipment you wish to run.
I tested my station using my string of outdoor LED bulbs (27w), running my modem and router (about 35w), charging my phone (about 20w), running a tablet with netflix streaming (about 25w) and an LED lamp from the living room (about 7w)
At just over 100w, the power station will run for around 4 hours with limited charging from the solar panel.
if i reduce the usage to 50w, (phone charger and LED lights only) i can get almost 10 hours out of the system.
Unfortunately, since the system only has a 10w panel charging it, all used power will not be replaced in one day. Since i dont use this a lot, the 10w panel will be fine, it takes about 3 days to charge back up to 100%. Upgrading to a 50w or 100w solar panel is in the works, but not really needed for my use.
Step 7: Running the Power Station and Many Uses.
I regularly use the station for watering my plants, charging my phone while sitting on the porch, and running my LED light string in the front yard. If i want to take the station camping, i just disconnect the pump and solar panel and toss it in the truck.
The pump bucket makes an excellent camp shower. Just fill the bucket with half way with cold water and fill the rest of the bucket with hot water warmed up on the campfire or stove. This is a big hit with my friends at the campsite. After a few days in the dust and dirt it feels amazing to have a shower in the woods without jumping into a freezing cold pond with a bar of soap. Bring a tarp to tie between two trees with a rope to make a nice shower enclosure.
Due to the extremely high fire danger on the west coast, this rig will help reducing the need to use fire (campfire, lantern, torch, etc) to generate light. You can use an LED bulb or string of bulbs to light the camp. This also saves money on white fuel for lamps and gas money for generators.
An added bonus to the old inverter/jumppack i used is the built in low volume high pressure pump to fill bike tires. The unit also has a low pressure high volume pump to fill pool toys or an air mattress.
Hope you enjoyed my project, it may help someone out in a pinch.
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