Monday, November 28, 2011


 TriMet's $370600 solar-power project for MAX at Portland State University will ...


Erik H. said...

This will be - at optimum performance - a 7.65kW solar panel installation. That means for each hour the sun hits these panels, it will generate 7,650 watts of electricity.

Enough to power 127 ordinary 60 watt light bulbs.

Meanwhile, just ONE Type 4 MAX car contains four 175kW motors.

In other words...the solar panels will accomplish...essentially nothing. The solar panel grid (at a quarter million dollars) won't even provide enough juice to turn one of the four traction motors in the most efficient LRVs in TriMet's fleet.

But, the solar panels will generate enough electricity to offset all of the lighting used at unused WES stations during nights and weekends when there is no service. Of course, TriMet could just turn the lights off...but solar panels are a far more sexier idea (and there's jobs involved, JOBS!) in installing those solar panels versus installing a $25 timer that would just shut off all the lights on the WES platforms and empty parking lots.

Max said...

Erik, by your math a type IV train requires 1.4MW (175kW * 4 * 2) of power just to turn the wheels.

Please substantiate your claim.

Erik H. said...

The motor on a S70 (Type 4) LRV is a 175kw motor, per Siemens' own datasheet.

If the solar panel grid has a capacity of do the math. 7.65kw is 4.3% of 175kw.

67,000kw (the stated generation of the solar panel system), divided by 365 and then divided by 24 is 7.65kw. Even if...EVEN IF, I was off by a factor of two (since, of course solar panels don't do a damn thing over night), you still have a 15kw system.

And...15kw is NOWHERE NEAR 175kw.

Unless you have some magic trick up your sleeve to justify that a 15kw system...or even a 20kw...or even a 30 kw...or even a 50kw system...can somehow generate enough watts to power a 175kw motor, then multiply that by four (four motors per car) and again by two (virtually all MAX trains run in two car sets)...

Max said...

My stereo is rated at 100W, yet it only consumes 20W when I listen to the radio.

Just because the motors are rated for a maximum of 175kW doesn't mean that they're sucking down that amount of juice 100% of the time.

San Diego's spec sheet says that their S70s use "130kW to maintain speed." So you can see that by the time you factor in time stopped, regenerative braking, or maintaining speed - your estimate is probably off by a factor of 5 or 10.

I'm not saying that the solar panels are a wise investment; I'm just pointing out how bogus your figures are.

... just like how you said TriMet had no contingency fleet.

... or how you said that TriMet releases the names of bus operators but not MAX operators.

I think you can make a valid point without having to stretch the truth.

Erik H. said...

OK, so if we "unexaggerate" the truth as you demand, what happens EVERY TIME A MAX TRAIN ACCELERATES? Load is increased. Yes, your stereo isn't blaring at full blast, but you aren't also cranking up the speakers either. A MAX train accelerates and decelerates repeatedly. It is not a constant load - you MUST plan for peak load, or else every time a MAX train accelerated you'd overload the system.

So where is TriMet's contingency fleet? After Al has posted posts here that confirmed that bus runs have been cancelled due to a lack of serviceable vehicles? All of the times when I am waiting for a bus that is scheduled but doesn't show up, and there's no a replacement vehicle...or does TriMet employ "Ghost Buses" that I can't see but everyone else can? If you want to prove me wrong, let's see the number of vehicles in reserve that are available for extra service each day.

What is the name of the MAX operator that didn't understand what a track bumper is? I still haven't seen that name published. If you want to prove me wrong, let's see a name.

Let's see the facts...prove me wrong. I'm waiting...

Max said...

"unexaggerate" the truth as you demand

I find this statement to be hilarious! When the truth is exaggerated it is no longer the truth -- it is in fact FALSE (i.e. A LIE).

Erik, you often have very valid points, but what I don't understand is why you don't just let them stand on their own merits, rather than losing all credibility by supporting the point with a bunch of bogus misinformation. If one part of what you're saying is bogus, then many people (myself included) tend to ignore everything else you're saying.

To respond to what you're written above re: MAX power usage - actually you're wrong. In this case you don't have to plan for peak load; because they're not actually running anything off of the solar panels directly. They're selling all of the power generated to PGE; so the power generated by the solar panels at any given point in time does not need to meet the potential peak load.

Of course, this discussion is really silly because nobody, including TriMet, is trying to power the trains in this manner.

Also: I don't know of many MAX trains doing 0-55 on the mall. That's where your 1.4MW comes from.

Contingency fleet.

The head mechanic (?) presented the state of the fleet to the board. You've got some unspecified, unsubstantiated "posts from Al." I don't need to prove you wrong, you need to prove yourself right.

I have no doubt that occasionally a bus doesn't show up -- but the onus is on you to prove that this is due to a lack of equipment, as opposed to any number of other reasons.

MAX operator's name

TriMet says they don't release the names; so the lack of the MAX operator's name out in public only supports that position. Your position that they routinely give out bus operators names is what I'm disputing. Claudine's name wasn't in the press until only recently. Why wasn't her name published back in Sept? October? Mary Fetsch did a lot of interviews back then. Surely there must be at least one of those where Mary gives out the operator's name?

Max said...

"If you want to prove me wrong, let's see the number of vehicles in reserve that are available for extra service each day."

I've already provided this...OK, I guess you'll make me look up the link again...sheesh...

Here's the board meeting. At 9:13 the head of maintenance (Tom Neilsen) says "...and we've got 26 contingency buses.". These are buses in "semi-retirement" used for "emergencies, or for a major accident where a bus will be out for 6-8 months." Then at ~10:54 he says that weekday peek demand is 501 buses, but there are 600 buses in the active fleet; thus (11:36) they have a spare ratio of 20%. These 99 buses are used for bus bridges, extra service, to sub for a bus that's being repaired, etc.

So I count 99 + 26 = 125 buses that could be used for this purpose.

Max said...

This document lists the existing substations as having a maximum rated power output of 750-1000kW; which is a far cry from the 1.4MW peak load you said would be required.