How to measure how much solar we need?
(hope this is right section) Brought home TT last month and now have basics taken care of and RV is road ready. Now starting to think about bigger long term projects. One project is, we would like...
Forum Discussion
Hi Almot,
Wow, only 28 amp-hours from 1000 watts of panels? I'm floored. On Dec 21 I get about 17 amp-hours from 256 watts of panels.
I agree that the first order of the day is to conserve. LED lighting at the prices we can get from Ebay is a no brainer.
Next on the list is stopping both heat build up in summer and heat loss in the winter. I use vent and skyline "cushions" and have insulbright covers for the windows, door, and a way to block off the cab area. Doing so means I can heat 100% electrically in winter using about 19000 btu's (~6000 watts), while keeping the propane furnace as a "back up".
Next stop is upgrading charging paths from the alternator. I added a second charging circuit, so I have twin #8 wire. This allows me to do 70 amps when needed. Even at highway speeds my system can not sustain 70 amps for long, so I've been known to limit the charging by turning off one wire, and also to shut down some of the loads.
What I can run is the fridge and the fan for the roof air. Running the fan allows me to cool down the RV using the dash air.
The Magnum inverter allows me to run what ever I wish from the batteries, but that energy has to be replaced. I have done experiments where I use 1300 watts to run the water heater. I watch the voltage on the chassis and use a duty cycle of five minutes on and ten minutes off. My "cut off" is 13 volts. If I see that I shut down some of the loads.
There would be room for improvement on the alternator by adding a remote regulator to take the load off the internal diodes. Another more expensive route would be adding a second alternator, dedicated to the house batteries.
One of the summer problems I still have is heat build up in the drive train. After I've driven for several hours it takes a heck of a long time to cool off--and of course that heat does rise and warms the RV considerably in the summer time. I've toyed with the idea of using a box fan under the rv to blow away the heat, but have not actually tried it.
I'm still "on the fence" about upgrading the solar. What I have works well, more by luck than good planning. Upgrading to more wattage might not make the difference I hope for. Living off the grid entirely with solar for electrical power is the goal. I would snow bird from November until March each year.
When I went to full time, I did purchase a Yamaha Sieb 3000 VA generator. I've since added remote start for that and combined with the hybrid inverter I can run everything I want to without fearing running down the battery bank.
The combination of the hybrid inverter and battery bank allow me to use just 15 amp shore power while retaining the ability to run every item I wish to at the same time. Of course, I can't exceed the 3000 watt rating on the inverter, but it is miles better than having to load balance and agonize about tripping a shore power breaker that I don't necessarily have access to.
If someone would make a truly flexible panel, I'd consider replacing the awning. That would be a wonderful way to have the best of both worlds. I.E. keeping the existing solar while adding a lot of capacity.
Wow, only 28 amp-hours from 1000 watts of panels? I'm floored. On Dec 21 I get about 17 amp-hours from 256 watts of panels.
I agree that the first order of the day is to conserve. LED lighting at the prices we can get from Ebay is a no brainer.
Next on the list is stopping both heat build up in summer and heat loss in the winter. I use vent and skyline "cushions" and have insulbright covers for the windows, door, and a way to block off the cab area. Doing so means I can heat 100% electrically in winter using about 19000 btu's (~6000 watts), while keeping the propane furnace as a "back up".
Next stop is upgrading charging paths from the alternator. I added a second charging circuit, so I have twin #8 wire. This allows me to do 70 amps when needed. Even at highway speeds my system can not sustain 70 amps for long, so I've been known to limit the charging by turning off one wire, and also to shut down some of the loads.
What I can run is the fridge and the fan for the roof air. Running the fan allows me to cool down the RV using the dash air.
The Magnum inverter allows me to run what ever I wish from the batteries, but that energy has to be replaced. I have done experiments where I use 1300 watts to run the water heater. I watch the voltage on the chassis and use a duty cycle of five minutes on and ten minutes off. My "cut off" is 13 volts. If I see that I shut down some of the loads.
There would be room for improvement on the alternator by adding a remote regulator to take the load off the internal diodes. Another more expensive route would be adding a second alternator, dedicated to the house batteries.
One of the summer problems I still have is heat build up in the drive train. After I've driven for several hours it takes a heck of a long time to cool off--and of course that heat does rise and warms the RV considerably in the summer time. I've toyed with the idea of using a box fan under the rv to blow away the heat, but have not actually tried it.
I'm still "on the fence" about upgrading the solar. What I have works well, more by luck than good planning. Upgrading to more wattage might not make the difference I hope for. Living off the grid entirely with solar for electrical power is the goal. I would snow bird from November until March each year.
When I went to full time, I did purchase a Yamaha Sieb 3000 VA generator. I've since added remote start for that and combined with the hybrid inverter I can run everything I want to without fearing running down the battery bank.
The combination of the hybrid inverter and battery bank allow me to use just 15 amp shore power while retaining the ability to run every item I wish to at the same time. Of course, I can't exceed the 3000 watt rating on the inverter, but it is miles better than having to load balance and agonize about tripping a shore power breaker that I don't necessarily have access to.
If someone would make a truly flexible panel, I'd consider replacing the awning. That would be a wonderful way to have the best of both worlds. I.E. keeping the existing solar while adding a lot of capacity.
