Rain is falling on our offices at Powerhouse, Oakland, California, which has me thinking. Wet roofs can be bad business. Good foresight can make those days go smoothly. The right team can save the non-roof work for rainy days. This includes things like hanging the inverters or installing conduit and pulling wire. I’m going to talk about one of those “indoor” activities. Today we are focusing on conduit, which seems like a small part of solar estimating. But, it can really affect your PV system cost and bid accuracy.
Conduit is a funny thing. As a solar estimator, you can dial in its cost pretty extensively. Every part is in a catalog and the labor to connect it all can be fairly granularly assigned. Bending conduit is the only thing that can vary wildly with installer skill level.
In this particular case, going granular isn’t exceptionally useful, especially if you have a short window to cost out your system. So just like with racking, posts, carports, roofing, trenching, really everything, you can create a “typical” version and then tweak it.
My last boss, Blake Gleason, actually did a variation on this method once and it is still the cleanest execution I have seen. To simplify your conduit costs calculations, you need to find a couple of “typical” conduit runs and then tally up all the pieces involved. Figure out how many 90’s, couplers, sticks of conduit, LB’s, Myers Hubs, straps (single and double), supports, offsets and anything else that went into the run. Put all those numbers down in a spreadsheet and then price every single piece out. Tally it up for the total length of run, and divide by the length. And suddenly you have a price per foot for a “typical” conduit run.
I recommend doing this for all of the different sizes of pipe you work with. Then you have a quick, reliable reference for your cost-per-foot of conduit. But wait, there’s more!
Now, find a complicated conduit run. Find a couple. Repeat the step of tallying those parts. With a “complicated” cost per foot you now have a way to create a scaling factor: A multiplier for all conduit runs when they become complex. That factor will help you start to build your cost intuition.
Alternatively, ask your field team to do this on real conduit runs and time themselves. It might take them a few more minutes to tally up all the parts. However, if they do it twice or three times you will have both material cost and labor hours associated with these conduit runs and they will have better insight into how long it takes to do one.
See? Rainy days don’t have to spell trouble for your deadlines. If you plan things carefully, you can make use of those days to do other essential tasks – and with a little legwork, you can build accurate methods for tracking even the most volatile pieces of your project. What are some of YOUR favorite tips and tricks for keeping track of these things? We want to know! Reply in the comments, find us on Facebook, LinkedIn or Twitter, or email us at firstname.lastname@example.org.