Notes from Windward: #68


PowerLab Progress

going for grid-tie

  March 3:

     The rather inconvenient amount of snow we had has pretty much melted by now, and we're getting to where we can get back to work on outside projects such as building a sturdy but portable mount for the PowerLab's solar panels. We're in open range country, and periodically thousand pound range cows wander through Windward looking for ways to scratch what itches, and we have to build accordingly.

      Photovoltaic panels work great, and they're a convenient way to generate electricity, but their per-watt cost is spendy so while they do have a role to play in Windward's "energy quilt," their role will be more along the lines of a supporting player rather than the central role that solar steam will play. But for now, they'll enable us to get the grid-tie aspect of our system working, and supply the boot-strap power we'll use to get other aspects of the system up and running.

the 4'x8' portable mount for the PowerLab's solar panels

     The two key components we're using in the PowerLab are Outback's MX60 Charge Controller and their GTFX 3524 Inverter Charger.

     If you're interested in more detail about those units, I'd invite you use the links above to access the manufacturer's website. Outback's user form is another great way to learn about how to get the most out of your individual situation.

     Over the next year, long-term readers of these Notes will detect a change in the way we're presenting information about some of our key projects. For example, we've purposefully not talked much about how we're wiring up the PowerLab because we're not licensed electricians, and while we do our best to build "to code or better," you'll need to determine what your local requirements are and go by those rules.

     In a similar vein we'll be using compressed air to get our steam- engine-powered electrical generator up and working since the engine doesn't care whether it's being pressured by steam or air, and compressed air makes for a gentle learning curve as we tinker with the operating software. Steam at 300° F. is most unforgiving.

     Likewise, a key part of the woody-biomass-to-methanol project involves the compression of carbon monoxide, carbon dioxide, oxygen and hydrogen, each of which have their own challenges. And so we'll initially work on teaching the control computers to compress air since that's the least problematic gas that we'll be working with. Once the kinks are worked out of compressing air using a combination of computer controlled pneumantic, hydraulic, mechanical and vacuum actuators, we'll move on to address the unique challenges brought by each of the other gases.

  March 8:

     Today saw the completion of the mount for the PowerLab's four 70-watt photovoltaic panels. Still want to do a bit more bracing on it, but it's far enough along so that we can start wiring up the panels next week.

280 watts of panels in place

  March 10:

     Today we secured the PV panels in place, and wired them in series to create a 48 volt charging array.


     At that point, it was time to connect the PV panels to the charge controller. It's a DC to DC converter that takes the incoming 48 volts and uses that to charge the 24 volt battery which in turn feeds the inverter.


Notes From Windward - Index - Vol. 68