Mike Haasl

No Kenneth, it's a fairly odd "engine".  It's not rotary...

Thanks for the offer Nick, you're just the kind of engineer I'm after :)  I'll shoot you a pm.

I don't want to post too much about the actual engine for fear of losing the ability to patent it for permies.com....

You just get credit in PEA for any PEP Animal Care BBs you've done.  So if you did 3 in PEP, that saves you 3 points that you don't have to do in PEA.  No need to repost or resubmit, just mention them when applying for your PEA badge.

This spring we will be holding a free BB20 event in conjunction with my visit to WL to sign the SKIP books.  The date is dependent upon when the printers get the books shipped to Paul but we're guesstimating it will be in April.  

This is a chance for anyone with a BB20 badge in the PEP Program to come out to Wheaton Labs for free.  It's an event where you work at your own pace and under your own direction on the BBs of your choice.  Or just watch the clouds go by.  There aren't instructors and it's pretty free-form but Paul will probably have a few BBs that he'd really like us to knock out so that we help the crew there.  Perhaps it will be harvesting firewood or Building hugelkulturs.  

Since it's a free event, we aren't all guaranteed to have access to everything we'd want.  For instance the excavator may or may not be available.  Or we might not all be able to play with full willow candy cans.

Since Paul loves you so much, boot-style food is also included.  That's a wide variety of vegetarian staples but we have to cook it ourselves and clean up after ourselves.  Tent sites are free but bunks would need to be paid for.

If you want to watch something really boring, Paul and I will be signing a gajillion books during the week as well.

We'll announce the date once we are confident in the printer's delivery timeline, likely no more than a month in advance.  We'll probably also come up with a way for folks to "sign up" officially so the team there knows how many people to expect.

So if you've been waiting for a time to get to WL for free, this is it.  Just get 20 BBs under your belt.  

Sorry Carl, I neglected to mention that the engine is a sort of slow piston compression device.  I'm thinking it would compress a hydraulic piston 4" on a heating stroke, then retract on the cooling cycle.  Those cycles would not be fast, maybe a cycle every 4-10 seconds.  So that's why I think it would need a small accumulator to average out those pulses for a downstream hydraulic motor.

I don't have a good feel for the cycle rate until we build one.  Or we find someone who's really good at calculating thermal effects on metals...   If it's 4 seconds per cycle, I calculate 1 liter/min at 338 bar (4900 psi).  I have no idea how much energy needs to go into it to get that power out but I'm assuming it's 30-60% more.  The key here is that this engine would take low grade heat differences and convert them into usable power.

I'd start with what temperatures you like or can stand (highs and lows, summer and winter) and also what summer humidity range you want.  

Then maybe the topography and aridness you could tolerate.  Once you have that bookended, draw a funny circle on a map of the US that encompasses those conditions.

It's no use falling in love with Alabama if you can't stand humidity or North Dakota if you can't stand the cold.  When you get below climate zone 5 it gets trickier to grow as much stuff as you could at zone 7.

I'm also guessing that to get a large enough accumulator to store enough power to get through 12-24 hours of use may cost more than an equivalent battery bank.  

So then using the heat engine to pump fluid into a small accumulator in order to meter it evenly to a motor/generator and then to the battery bank may be best...

My go-to page is This One.  The badge images at the top all take you to their associated badge page.

I'm looking for a simple solution to get perennial trees to get through the winter.  I'm thinking this would do the trick and I'd definitely like to avoid burning oil (waste or otherwise) to support my trees.  Or fiddling with anything throughout the winter.  Kind of a "set it and forget it" solution.

It seems like opaque or semi-translucent would be better than transparent so that it doesn't heat up too much on sunny winter days.

Thanks Marc!  So if it is 240A and 12V, I think that is 2,880 watts.  

Sweet, that's great to hear Marc!  Do you know how many watts (or volts) that alternator is putting out?  Trying to get a feel for how much power that amount of hydraulic storage would meaningfully produce.