Snow Pod for Cheaper Machine-made Snow

[thebigo]

Is 75 gpm max or typical?

Is 200 psi measured at the pump or nozzle?

For the sake of this discussion, water is incompressible. Pressure is required to overcome flow loss only.

The reservoirs are buried under water bars, a 20,000 gallon tank is roughly 60' long. The reservoirs refill naturally or a resort can chose to refill at their discretion. Those in the industry are more knowledgeable than I but my understanding is that utility rates fluctuate?

 

[drjeff]

If I am ultimately proven wrong, I will 100% Own it!

Just not seeing how short of a minimalistic nod. That it's financially worth it to keep the doors open 24/7

 

[thebigo]

If I am ultimately proven wrong, I will 100% Own it!

Just not seeing how short of a minimalistic nod. That it's financially worth it to keep the doors open 24/7

Microbrew tonight? What's your flavor?

 

[thebigo]

Energy matters more and more every day. It is nuts to allow a gallon of water to fall on rime then pump it back to rime from Woodward. That is 1970s thinking.

Edit - are base area pumps typically positive displacement? Who is the common OEM?

 

[joshua segal]

Thanks, folks, for so many good comments.

The formula for snow is moisture, below freezing temperatures. With snow guns, it also requires pressure. I think the real issue is not whether it is possible to make snow with the ReNew Snow pods, but what percentage the melting snow from the hill can be recovered so that it doesn't have to be pumped back up the hill again. That's what the prototype should be able to assess.

If that proves to be satisfactory, there are significant regulatory issues that will have to be resolved. Ultimately, it appears that it would be a zero-sum game. If I take "x" million gallons less water from the bottom of the hill and recycle "x" million gallons of water on the hill, it would seem to me to be logical that that regulatory issue is resolvable, but clearly, that will be on a state-by-state basis.

 

[Newpylong]

Is 75 gpm max or typical?

Is 200 psi measured at the pump or nozzle?

For the sake of this discussion, water is incompressible. Pressure is required to overcome flow loss only.

The reservoirs are buried under water bars, a 20,000 gallon tank is roughly 60' long. The reservoirs refill naturally or a resort can chose to refill at their discretion. Those in the industry are more knowledgeable than I but my understanding is that utility rates fluctuate?

75 GPM is middle of the road (for a fan) which is why I picked it. Most fans running in a really good wet bulb with convert 150 GPM of water into snow.

200 psi is measured at the nozzle. Pressure is not only required to overcome head and friction loss, it is a necessity for nucleation in man made snow. Something (ie a pump) is going to have to pressurize the water before sending it to the equipment.

I've already described how the theoretical 20,000 buried tank will be sucked dry in 4 hours by a single fan gun running with half of its banks open... let's bump that to 6 hours assuming the water bar (source) is flowing fairly rapidly during snowmaking operations. From an operational perspective that is not valuable.

 

[RichT]

How will they keep these "pods" from filling up with silt? I've read there Investor Presentation, on page 13 (not numbered 13, superstition?), I don't see how they get to the 198 resorts using their system in 2031. I call BS on the whole thing.

 

[Newpylong]

Energy matters more and more every day. It is nuts to allow a gallon of water to fall on rime then pump it back to rime from Woodward. That is 1970s thinking.

Edit - are base area pumps typically positive displacement? Who is the common OEM?

Any water that melts off Rime is going to end up in the Roaring Brook and thus Snowshed. Woodward is used when the local sources aren't replenishing the two ponds fast enough.

 

[joshua segal]

How will they keep these "pods" from filling up with silt? I've read there Investor Presentation, on page 13 (not numbered 13, superstition?), I don't see how they get to the 198 resorts using their system in 2031. I call BS on the whole thing.

You make a good point. IMO, that is an important issue, but the bigger issue has been discussed extensively on this thread and that is: "How much water is actually recoverable?" If the prototype shows adequate recoverable water to make the financial difference that ReNew Snow claims is possible, issues such as silting not to mention other debris: pebbles, leaves, twigs, etc. will need to be addressed.

 

[jimmywilson69]

I just don't see this being viable. Its a great idea in theory, but the fact of the matter is that you're never going to get enough Volume and you still need a lot of pressure at each gun to make snow. Its just not scalable...

 

[drjeff]

I just don't see this being viable. Its a great idea in theory, but the fact of the matter is that you're never going to get enough Volume and you still need a lot of pressure at each gun to make snow. Its just not scalable...

One of the few places where I *might* see it as a reasonable option, is a small sized snowmaking system such as Mad River Glen's. A system that uses 100's of millions of gallons of water a season, as many mid sized and certainly large sized systems use, that's a much different animal to hand the water demand for

 

[kendo]

One of the few places where I *might* see it as a erasonable option, is a small sized snowmaking system such as Mad River Glen's.

... or a Town or parent that wants to cover the local sledding hill.

 

[JoeB-Z]

Where are you going to store water at elevation or close to every (fan) gun that is using on average 75 gallons per minute? 20,000 gallons would last 4 hours. Youre going to bury a tank per gun? To last 4 hours? What about pressurization of the water? Even IF you could get adequate flow rate, the pressure must be boosted. Once you start adding little bitty pumps all over...

It doesn't add up and once you begin to figure out scale, any advantages dry up (no pun intended).

Summit water storage (where an operator is lucky enough to have room and permitting for them) on the other hand can make a real world difference.

Agree. A few comments as a mechanical engineer and patent attorney. I want to see an energy balance and comparison to an existing system all the way through to the objective, making a certain amount of snow. The patent applications (there is also an issued earlier patent) are for water distribution systems. Not for the rest of the system to actually make snow. To set this system up you need a head of water coming in say 200 feet above where you make snow, I think the idea is that when you are not making snow, you are running a turbine to store electrical energy in a battery. Then you can divert the 100psi or so flow of water into the snow gun and use the energy to run a fan gun. This is basically a series of underground hydroelectric dams with a water storage system and an electrical energy storage system. The entire system is a tremendous amount of on mountain hardware per snow gun.

I also just realized that as you are running the turbine for power, you need to retain enough water in the reservoir to actually make the snow. So the recharge rate/reservoir volume becomes important.

Also I see now that "But in most cases, ReNewSnow will need to install a booster pump, drawing power from the electric service supplying the snow-gun." So now you need power at each gun,

I also see that the power generated may be only for the diverter valve.

 

[joshua segal]

FYI: Installation of the prototype had to be delayed due to the magnitude of the waterflow over 24 hours following a rainstorm.

As to a booster pump drawing electricity: That's not where the savings comes from; it comes from not having to pump the water up the hill.

And remember, this is a development project. If ReNew Snow knew the result of the experiment, they'd either be marketing their system or closing up shop. Perhaps we can refer to the SnowPod as "Schrodinger's Cat" for now.

Please keep the comments coming. Some of them have been helpful.

 

[kancamagus]

I don't have any comments about running a prototype test of this concept. The napkin math posted here seems like it may be tough to work out, but the concept of trying to keep water still at high elevation to avoid pumping it back uphill makes sense. It also seems like if you could just add a lot more water storage at high elevation (in the form of septic-tank-like underground polyethylene tanks), this might be able to achieve a similar benefit that can tie into existing snow making systems.

The only comment I will add is in regards to this graphic from their website:



They couldn't even click the spell check ignore button in Microsoft Office before taking a screenshot.

 

[machski]

Going to use crotched as an example because they are 100% fan gun and the pond is front and center.

When a drop of rain falls on crotched it has potential energy. From the perspective of snowmaking, the potential energy is a function of the elevation difference between the pond and the location where the drop hit the mountain. The potential energy is 100% solar. Currently the aforementioned potential energy is lost while the drop finds a stream enroute to the pond. The potential energy is then regenerated in the winter at peak rates while pumped back up to the snow gun.

If you could somehow figure a method to store that drop of water at the snowgun you would not have to consume the electricity to pump it back up the mountain.

I have not looked into the ROI but as an engineer with nearly two decades in the hydro industry the lack of snowmaking reservoirs at elevation has always bothered me. I also have no idea how many gallons a fan gun consumes but a gravity fed polyethylene reservoir below the frost line with submersible centrifugal pump is intriguing.

The example of crotched is convenient but think how far killington pumps their water? Miles?

The answer to why is in the permitting of trying to do so, especially when talking about building elevation reservoirs on NFS land. Research Loon Mountain, they have the high elevation Loon Pond they used to use for snowmaking. It is a dead pond, no real outflow so no aquatic life. They wanted to pump river water from the Pemi during high flow to refill. Yeah, that didn't go over well with lawsuits filed from far away blocking the refill plans. Nothing easy about building elevated reservoirs on public Forest lands, even if trying to use existing water bodies.

 

[Rogman]

Seems sketchy...
What's the cost of raising 200,000 gallons of water (enough for 1 acre foot of snow) 1000 feet? That's where the savings comes from.
200000 gallons x 8.4 lbs/gallon x 1000 feet = 1,680,000,000 foot-lbs of work
1,680,000,000 foot-lbs x 1 kilowatt-hr/2.655e+6 foot-lb = 633 kilowatt hrs
633 kilowatt hrs x $0.25/kilowatt hr = $158.25

Even factoring in friction losses (which affect both sides of the equation), I think I'll keep my money in my pocket.

 

[joshua segal]

Water is not only brought from the bottom of the hill, but in many cases, from miles away. According to a quick scan of the internet, an average large east coast ski area uses 250M gallons per season.

 

[joshua segal]

Following the current melt cycle, ReNewSnow finally got all their electrical connections completed and declare phase one of their system test a success. The photo shows their gun producing snow. How much and for how long are still TBD.

 

[joshua segal]

The content of this thread was discussed a bit on page 500 of https://forums.alpinezone.com/threads/vail-sucks.143038/page-500
ReNew Snow was dissolved in December 2023. Water flows were analyzed and the empirical findings were that the actual flows exceeded the predicted flow. The company used some of its funds to build a prototype. The prototype worked exactly as planned using an HKD snowgun. Anyone who has done product development knows that a prototype doesn't just become a product.

The development funds, approximately $400K were used for getting the patent, doing the water flow studies and building the prototype. Additional funding for the transition of the prototype to a product proved elusive.

Any more questions, ask away. If I know the answers, I will share them.