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peakbagger
01-20-2011, 10:00 AM
So whats this to do with hiking? Well anyone who has hiked up nineteen mile brook trail has seen the dam and wondered what it was there for, well here is some background and a story about a recent upgrade.

http://www.newhampshirelakesandmountains.com/Articles-c-2011-01-18-153006.113119-Hydro-plant-upgraded-to-power-Auto-Road-Base-Station.html

10 kw doesnt sound like much until you realize that this is 10 KW - 24 hours per day and year round. I expect that if the system and dam wasnt in place long ago, it would never make sense to install a new system, but since it was there, might as well maximize the output.

erugs
01-20-2011, 10:05 AM
Very interesting story -- love having the background information about the Nineteen Mile Brook dam. Just imagine... Hope this project works out.

MichaelJ
01-20-2011, 11:36 AM
Neat! I have to admit, the dam seems undermaintained to be this well-utilized. But of course the real power comes not from the impoundment, but from the hydraulic head of the penstock.

Couple of nits about the article, though:


Improvements were made in 1995, cutting down on time-consuming and costly maintenance, he explained. The Honeymoon Dam on the east side of Route 2 is the start of the penstock that feeds the hydro-station as well as the fire sprinkler system. An eight-inch iron pipe runs next to the Honeymoon Cottage

East side of Route 16? Honeymoon Dam?


If all works out as anticipated, the financial payback will only take four years. The current $12,000-a-year cost of electricity will should be reduced to nil by the early months of 2015.

Shouldn't the cost of electricity be nil right away? Doesn't this mean the project cost was around $48,000 and so the project cost will be recouped by early 2015?

RoySwkr
01-20-2011, 05:02 PM
As mentioned, the article is sketchy. I would have thought that the dam originally supplied water only (Aqueduct Path) until tougher drinking water standards made that impossible, and maybe was converted to power only in 1995.

Kevin Rooney
01-20-2011, 05:58 PM
...Shouldn't the cost of electricity be nil right away? Doesn't this mean the project cost was around $48,000 and so the project cost will be recouped by early 2015?

Well, yes and no. Look at it this way: instead of paying the utility company $1,000 a month, they'll be paying the same $1,000 a month to pay off the loan on the borrowed money. The loan will be paid off in 48 payments, or 4 years (2015).

Then, it's "free", except for maintenance and repairs.

I have a PV system, where I have calculated that our initial investment will be recouped in 7 years if the rates remain unchanged. If they go up, it will be sooner; if down, then longer.

What do you think the odds are that electrical rates will drop ....

smitty77
01-20-2011, 06:40 PM
What do you think the odds are that electrical rates will drop ....
We've owned our house now for 7 years (coincidentally your time horizon for payoff) and if anything my monthly electric bill has stayed the same or gone down. I have bills for the last 2 years to verify that the rate is actually less now than in March of 2009. I make a mental note of the kWh usage month to month and compare it to the previous 12 months (which are conveniently displayed in a sidebar table on my bill) and we tend to use roughly the same amount of power year-to-year.

Where am I going with this? A coworker just leased a PV system for his home with a 20 year agreement (actually a power purchase agreement). The lease payment is about the same as his current electric bill and covers maintenance/replacement of the panels and the inverter for that time span. So he still pays month-to-month but has a lower carbon footprint. The big sell on this program: Their claim of dramatically increasing rates for conventionally supplied electricity over the 20 year period, citing historical increases of 6% per year over the previous 20 years. http://www.sunrunhome.com/why-solar/save-money

I'm not sold on this enough to lock myself into a 20 year agreement that needs to be transferred (or bought out if the new owner doesn't agree) if I sell my home before the end of the lease. At least based on my own personal experience. I'm going to use my co-worker as the perfect guinea pig to see if it makes sense over the next couple of years.

Getting back on topic - I applaud the MTW Auto Road for making efforts to be more environmentally friendly in their operation, but I tend to see these corporate steps to renewable energy as more of a marketing tool than anything. But it helps the planet in the long run, so it's all good.

psmart
01-20-2011, 08:39 PM
View from downstream showing the overflow:
http://i176.photobucket.com/albums/w199/psmart/P8020024.jpg

View from above showing the trash-rack around the penstock inlet:
http://i176.photobucket.com/albums/w199/psmart/P8020028.jpg

Kevin Rooney
01-20-2011, 09:25 PM
[thread drift on]

smitty77 - In general, the trend has been for electrical rates to increase steadily, especially for those utilities who depend upon carbon fuels for a large percentage of their generation. If your utility has actually lowered the kwh charge, count yourself fortunate. Mine has increased about 2.5 cents/kwh in the last 3 years to about $.145/kwh. So, despite a flat overall usage level, my bill steadily increased.

Am pretty sure federal tax credits are available regardless of the state, but state rebates vary, and I don't know what state you and your co-worker live in. In CA, between the state and federal rebates/credits, the cost for a PV system is subsidized about 50%. Personally, my outside limit for payback on most capital investments is 7 years, so 20 years give me the shudders. In all fairness, there may be others considerations of which I'm not aware which might change my mind, but on the face of it, I have reservations about such a lease arrangement. [/thread drift off]

smitty77
01-20-2011, 11:57 PM
Mine has increased about 2.5 cents/kwh in the last 3 years to about $.145/kwh. So, despite a flat overall usage level, my bill steadily increased.

While mine has gone from 0.091 down to 0.080. Is it an east/west thing?



Am pretty sure federal tax credits are available regardless of the state, but state rebates vary, and I don't know what state you and your co-worker live in. ..... ... 20 years give me the shudders. In all fairness, there may be others considerations of which I'm not aware which might change my mind, but on the face of it, I have reservations about such a lease arrangement. [/thread drift off]
This is also why I haven't given the program more consideration. All rebates go to the company that owns the panels. The upsides are:

Very low cost installation - up front of around $2300.

They monitor your system remotely 24/7. If any part of the system underperforms, they will come out and repair or replace it. This includes damage to any of the panel array and the inverter system.

It allows those of us with minimal financial resources to get mostly off the grid for the price of our current monthly electric bill.



But I'm with you - 20 years is a LOOOONG time to be locked into an agreement.

MichaelJ
01-21-2011, 06:43 AM
When you look at how much the upstream side of the sluice gate is buried in sand and rocks you really get a feel for how powerful the brook is to be able to bring all that to the dam in the current.

smitty77
01-21-2011, 11:01 AM
When you look at how much the upstream side of the sluice gate is buried in sand and rocks you really get a feel for how powerful the brook is to be able to bring all that to the dam in the current.
Was all of that material brought by the current, or was it back-filled at some point to dissuade it's use as a swimming hole when the dam was no longer needed as a water supply reservoir and purely as a means to collect a head of water at a higher elevation? It sure is impressive if it was all carried there by the current.

psmart
01-21-2011, 11:16 AM
Was all of that material brought by the current, or was it back-filled at some point to dissuade it's use as a swimming hole when the dam was no longer needed as a water supply reservoir and purely as a means to collect a head of water at a higher elevation? It sure is impressive if it was all carried there by the current.

I'm pretty sure it's due to natural movement of the gravel. Dams have to cleaned out regularly because the material collects there. As for the head on the penstock, that's established by the height of the weir. If the gravel were absent, the water would fill to exactly the same height in a few minutes or hours, depending on stream flow.

Kevin Rooney
01-21-2011, 11:17 AM
When you look at how much the upstream side of the sluice gate is buried in sand and rocks you really get a feel for how powerful the brook is to be able to bring all that to the dam in the current.

Flowing water is strong. I remember visiting the White River Campground with my wife and Brutus - it's the trailhead for the Rainier approach via the Ingraham Glacier. As we were walking around, stretching our legs, we could hear this muffled crashing and banging coming from the general direction of the river, so we walked to an overlook, and studied the water. Finally we figured it out - the river, created by glacial runoff, was pushing boulders down the riverbed. Some of them were 3' or so in diameter. It was mid-afternoon, so the river was at peak flow.

As another reminder of how strong flowing water is - in the West, and especially Southwest, flashfloods are not uncommon, and motorists are reminded to never drive thru flowing water, as it only takes 6 inches to overturn a vehicle, and there are ample videos to demonstrate that, some with rather tragic results.

peakbagger
01-21-2011, 12:27 PM
Sediment fills up the backsides of dams naturally. Most of the dams along the rivers you see are not much deeper than the lowest opening of the dam. The impoundment at the gorham papermill is a good example, when they drain the rvier down for maintenance, its one big mud flat. There is a forebay on that dam so every few years they close the gates and dig out the gravel from the forebay. The hydro station in Berlin is the same, once a year PSNH bypasses the dam (creating an incredible batch of whitewater) into the old river channel and digs out the area in front of the inlet to the penstocks.

Heck if there is gold bearing soils upstream, one of the trciks of the trade is to dredge out areas behind obstructions as the heavier gold will tend to drop out upstream of the obstruction. Over many years the lighter gravels will be displaced during spring flooding, slowly increasing the gold content. Unfortunately the closest recognized gold bearing soils are in the watershed of the Swift River in Western Maine, so no use dredging 19 mile brook.

Dr. Dasypodidae
01-24-2011, 02:12 AM
Was all of that material brought by the current, or was it back-filled at some point to dissuade it's use as a swimming hole when the dam was no longer needed as a water supply reservoir and purely as a means to collect a head of water at a higher elevation? It sure is impressive if it was all carried there by the current.

Other good examples of measureable stream bedload are the sediments infilling behind the V-notch weirs in the 12 sub-watersheds of U.S.F.S. Hubbard Brook Experimental Watershed in West Thornton, N.H., which must be cleaned out at least once per year.