# New electricity distribution infrastructure or distributed generation? **URL:** \ **Category:** Great Debates\ **Created:** [March 8, 2009, 9:13pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764 "2009-03-08T21:13:03Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 8, 2009, 9:13pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/1 "2009-03-08T21:13:03Z")
For the sake of this thread let us please make the assumption that we do indeed need to significantly reduce our CO2 emissions and that renewables will be a large part of how that is done. This is not the thread to debate whether or not this assumption is correct but instead is debate the how: utility grade or in a distributed manner. Incentivized it also has its own thread. Our transmission infrastructure is in poor shape. Utility level generation of power in solar and wind farms located where those resources are best will require running new efficient transmission from those locations to where the power will be needed. One solution for the intermittency of wind and solar is to balance them out across a supergrid with a [high voltage direct current grid](http://en.wikipedia.org/wiki/HVDC) (HVDC). > [@](#): > > A number of studies have highlighted the potential benefits of very wide area super grids based on HVDC since they can mitigate the effects of intermittency by averaging and smoothing the outputs of large numbers of geographically dispersed wind farms or solar farms.[18] Czisch’s study concludes that a grid covering the fringes of Europe could bring 100% renewable power (70% wind, 30% biomass) at close to today’s prices. These infrastructure investments can be quite sizable. Wind farms in particular require these sorts of investments if they are to play a major role (20% plus) in the future. Another solution is avoiding major transmission infrastructure investment by minimizing the need for as much power, especially during peak power demand periods (when the system is most overloaded), to be sent through them. A major part of that tactic would be [distributed generation.](http://en.wikipedia.org/wiki/Distributed_generation) Among those options is locally generated solar, on individual home and business and factory rooftops and integrated into the building itself in new construction. This approach is attractive because as a resource it is best when peak demand hits most - daytime during Summer. Utilities could even own the equipment placed on a factory’s roof, giving a discount rate to the factory as rent and selling the excess to other local users. Some more rural locales can use local wind generation and some industries can use cogeneration to good effect as well. [Local biomass electricity generation](http://www.xconomy.com/seattle/2008/12/17/will-biomass-power-the-utilities-of-the-near-future/) is also proposed as part of the mix. And there is the possibility of storing power locally to release to handle the spikes during the peaks that most stress the transmission and production infrastructure, either in [multi-megawatt sized maegabatteries](http://www.autobloggreen.com/2008/07/11/altairnano-2mw-battery-passes-tests-could-help-green-the-grid/) at the level of local substations, or as EVs of all stripes become commonplace, in [vehicle to grid](http://www.greencarcongress.com/2007/04/pge_demonstrate.html) (V2G) applications. Of course the two are not mutually exclusive but it does seem that one of the advantages of the distributed approach is to limit how much we need to invest in improved transmission infrastructure and that we really should pick a direction sooner rather than later. Which direction is preferable? ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [March 9, 2009, 10:22am UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/2 "2009-03-09T10:22:51Z")
solar and wind are not solutions in themselves. They suffer when it gets dark and when the wind drops respectively. You need something for baseline load. Currently that something looks as if i’s going to be nuclear power. I’ve read great things here about Pebble-bed nuclear reactors. If what I’ve read here can be commercialised, and people get over their fears of nuclear power, then you could have a distributed network of PBNRs, basically solving the problem with minimal disruption. Indeed they’d actually remove a lot of the problems of power distribution. No more pylons. Automatic fail-over. And more. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 9, 2009, 12:41pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/3 "2009-03-09T12:41:09Z")
Any opinions that have to do with the question of the op, **quartz**? ---
**Author:** ![Sinaijon](https://avatars.discourse-cdn.com/v4/letter/s/dc4da7/32.png) [@Sinaijon](https://boards.straightdope.com/u/Sinaijon)\ **Post date:** [March 9, 2009, 1:34pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/4 "2009-03-09T13:34:16Z")
You are going to have to have some some sort of mix. HVDC is only more efficient for hugely long runs, with no taps. For local distribution, it’s just not cost effective, and the losses incurred in transforming voltage up and down quickly overwhelm any efficiencies you gain in long run transmission. So it might work for joining centralized power sources, like your wind farm or solar panel farm. But the majority of the grid will need to stay AC The same disadvantages of HVDC for local distribution are also a drawback of solar. Solar generates DC, which in order to be effectively distributed needs to be transformed into high voltage. The losses incurred at low voltages add up quick. A solar panel a block away at 120V is basically usless to you. Converting DC is much more expensive than converting AC. With AC, a simple transformer, like the green boxes or transformer poles on every block, sometimes every house, lets the transmission stay at high voltages to minimize losses. That would be cost prohibitive for DC. So while having a solar panel array on a building might work for that building alone, it really won’t be able to supply power elsewhere without some hugely expensive converters to up the voltage for distribution to the next building over. ---
**Author:** ![Walker\_in\_Eternity](https://avatars.discourse-cdn.com/v4/letter/w/46a35a/32.png) [@Walker\_in\_Eternity](https://boards.straightdope.com/u/Walker_in_Eternity)\ **Post date:** [March 9, 2009, 2:41pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/5 "2009-03-09T14:41:01Z")
I did some work on this in the past, as stated by \*\*Sinaijon \*\* HVDC is great for long distance runs, but AC is better locally. For an ideal network you could have intercountry/continental HVDC (assuming it was possible to get the individual nation states to find agreement as to operating it etc) and local AC distribution. From my own (unpublished) work: > [@](#): > > It is possible to use HVDC for economic transfer of large bulk power… (but)…different AC transmission lines use difference voltages and frequencies and phases. In order to transfer power from one system to another synchronisation between networks is required. Synchronisation therefore requires expensive rectifiers and inversion equipment, because of this HVDC is often used to link different AC systems together. Of course converting AC voltages to DC is also not without cost implications. In essence short range low voltage transmission is more efficient and cheaper using AC, but long distance high voltage transmission, including the cost of the converter is more economically viable using DC voltages. > … > There has been a move towards a global hypergrid, connecting whole continents, so that during times when there is extra power available it can be transmitted to parts of the world that require power at that time. To this end a DC connection has been made across the English Channel between Britain and Europe, particularly to France where a surplus of power from their extensive nuclear power generators can be utilised at peak times in Britain. > … > Recently HVDC has been used in parts of the world such as China, where up to 500kV DC Transmission lines are in use. Consequently much of the research in this area has been carried out in China ---
**Author:** ![Gangster\_Octopus](https://avatars.discourse-cdn.com/v4/letter/g/a8b319/32.png) [@Gangster\_Octopus](https://boards.straightdope.com/u/Gangster_Octopus)\ **Post date:** [March 9, 2009, 6:06pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/6 "2009-03-09T18:06:26Z")
Senator Harry Reid has just introduced a bill to help create a National EHV Overlay ( Basically a Green Superhighway that would transfer renewable eerngy long distances). Not every house and busioness is suited to rooftop solar, of course. Some are simpy too shaded, some exist in areas where sunlight is not very ideal or are not postiiosned ideally. In fact, if it weren’t for the tranmission problem this would be a no-brainer. Bulilidng solar, wind and biomass facilities in the most favorable places is economically more efficient. However, transmission IS a problem. So personally I do not see either as being a stand-alone solution. However, my opinon (and I work in the field) is that building transmission to large utility size solar and wind installations (and geothermal and biomass) is the way to go for the large part, at least out west (where I do most of my analysis). ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 9, 2009, 8:59pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/7 "2009-03-09T20:59:17Z")
**Siniajon** and **Walker** , How does [net metering](http://www1.eere.energy.gov/solar/net_metering.html) work then? > [@](#): > > With net metering, the customer’s electric meter will run backward when the solar electric system produces more power than is needed to operate the home or business at that time. An approved, utility-grade inverter converts the dc power from the PV modules into ac power that exactly matches the voltage and frequency of the electricity flowing in the utility line; the system must also meet the utility’s safety and power-quality requirements. The excess electricity is then fed into the utility grid and sold to the utility at the retail rate. … Grid-connected PV systems can also help utilities avoid the cost of additional power generation, increase the reliability and quality of electricity in the grid, and produce power at times of peak usage, when utility generation costs are higher and they often need the extra power. ---
**Author:** ![Gangster\_Octopus](https://avatars.discourse-cdn.com/v4/letter/g/a8b319/32.png) [@Gangster\_Octopus](https://boards.straightdope.com/u/Gangster_Octopus)\ **Post date:** [March 9, 2009, 9:09pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/8 "2009-03-09T21:09:51Z")
> [@DSeid](#): > > **Siniajon** and **Walker** , > > How does [net metering](http://www1.eere.energy.gov/solar/net_metering.html) work then? I might be able to answer, but I am not sujure I understand what you are asking. Net Metring is for rooftop solar and such (depending on the size of your property of course it doesn’t have to be on the rooftop). THe PV DC power is converted to AC using an inverter. It is genreally done right at the site of the solar panels and energy delivery is not really an issue. Since energy cannot be stored efficiently (there are ways, but not very cheap) it must be used as it is generated. If the house is not using it then it can literally run somone’s meter backwards and return energy to the grid to be used somewhere else. net metering gerneally refers to the fact that most people do not have time-of-use meters, so folks get paid only what they return to the grid in excess of what they use between meter reads. So while you may return a lot of energy during the day because you are at work, you offset that usage with energy you take off the frid at night. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 9, 2009, 9:49pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/9 "2009-03-09T21:49:45Z")
Sorry if I was unclear **Gangster**. I understand that. My confusion is with **Sinaijon** ’s statement that > [@](#): > > A solar panel a block away at 120V is basically usless to you… while having a solar panel array on a building might work for that building alone, it really won’t be able to supply power elsewhere without some hugely expensive converters to up the voltage for distribution to the next building over. and how that jives with the efficacy of net metering and the US Dept of Energy’s take that feeding excess solar energy back into the grid is cost effective and helps deal with peak demand. My proposal is merely the same with the difference that the utility owns the solar panels and sells the electricity. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [March 9, 2009, 11:26pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/10 "2009-03-09T23:26:13Z")
> [@DSeid](#): > > Any opinions that have to do with the question of the op, **quartz**? Umm.. yes. As I said. You’re concerned with issues of power distribution and as I said, PBNRs allegedly solve this because the power is generated locally. Of course, it has yet to be put to the test. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 10, 2009, 1:33am UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/11 "2009-03-10T01:33:13Z")
Ah. I see your point now. Sorry. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [March 10, 2009, 2:29am UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/12 "2009-03-10T02:29:36Z")
> [@DSeid](#): > > Sorry if I was unclear **Gangster**. I understand that. My confusion is with **Sinaijon** ’s statement that > > > [@](#): > > > > A solar panel a block away at 120V is basically usless to you… while having a solar panel array on a building might work for that building alone, it really won’t be able to supply power elsewhere without some hugely expensive converters to up the voltage for distribution to the next building over. > > and how that jives with the efficacy of net metering and the US Dept of Energy’s take that feeding excess solar energy back into the grid is cost effective and helps deal with peak demand. My proposal is merely the same with the difference that the utility owns the solar panels and sells the electricity. I think **Sinaijon** ’s point was regarding a 120V DC solar panel trying to send its power a block away via DC. With Net Metering, your solar panel power is converted to AC before tieing into the grid. Any excess power flowing back into the grid then gets its voltage raised by the same transformer that normally drops the line voltage to your house voltage. So you get the efficiency of higher voltage transmission using the already-existing system. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 10, 2009, 3:46am UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/13 "2009-03-10T03:46:57Z")
Well yeah but it was said to explain why excess electricity generated by a factory roof’s solar panels could not be used to power other local demands in a distributed generation system. The converters do not seem to be so “hugely expensive” and are already in use. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 12, 2009, 4:23am UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/14 "2009-03-12T04:23:09Z")
A pertinent [article.](http://seekingalpha.com/article/124774-senate-draft-legislation-a-boon-for-solar-smart-grid) > [@](#): > > Draft legislation from U.S. Senate Majority Leader Harry Reid would radically expand the federal government’s power to speed the siting of transmission lines from remote renewable energy zones to the nation’s population centers. The quality of the transmission infrastructure limits utility grade renewable deployment but as that article explains, this aint cheap stuff to do. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 12, 2009, 3:31pm UTC](https://boards.straightdope.com/t/new-electricity-distribution-infrastructure-or-distributed-generation/488764/15 "2009-03-12T15:31:30Z")
That article had me got me to this executive summary of the Joint Coordinated System Plan for infrastructure development (pdf). They attempt to compare some of the costs and benefits of enough infrastructure investment to bring wind up to 5% (using resources closer to population centers and not tying together with a long distance HVDC system) vs a 20% scenario. It’s a limited value study given the nature of assumptions made and the fact that it explicitly excludes accounting for cost savings going forward but for anyone curious it is an interesting, albeit confusing read. > [@](#): > > To determine the net costs and impacts of each scenario, the JCSP’08 compared each scenario to a common base case, which contains the transmission constraints inherent in the existing system. Each scenario is evaluated by comparing the costs and benefits (production cost savings) of the base or constrained case to those of the scenario to determine the net impact of the transmission and generation assumed in each scenario. However, due to time constraints, the economic impacts have been calculated as point estimates for the year 2024 alone, rather than as a full year-after-year stream of benefits and costs. Although these estimates are offered in future value terms (2024 $), the reader should not assume that the costs and benefits represent cumulative benefits over a number of years; estimated capital costs are represented as if all of the new wind and fossil generation and transmission were built overnight at the start of the examined year. For that reason, this study does not attempt to estimate cost-effectiveness results for the two scenarios studied… the remaining resources were selected by a least cost regional resource forecast model to fill in around the wind > capacity … > > …As might be expected, generation investment costs would be significantly higher under the 20% Wind Energy Scenario than under the Reference Scenario, but energy production costs would be lower with greater wind-power use, and those savings would increase over time. … > > … In these scenarios, only 15% of the wind generation is counted as a capacity resource for reserve calculation purposes. This is because wind generation is only available when the wind blows, and is not available and dispatchable by system operators during all time periods. Since system operators can only count on fully dispatchable and predictable resources (such as fossil and nuclear resources and hydro storage units) for reliability purposes, less of the wind resource can be counted toward regional and Interconnection-wide reserve margins. Changes in loads, technologies and costs (including environmental or carbon costs and the capability of dynamic response and smart grid technologies to firm intermittent wind generation) could significantly change the pattern of generation capacity expansion and should be studied through further scenario and sensitivity analyses. … > > …The Reference Scenario assumes that wind generation from relatively local, on-shore sources produces 5% of the U.S. Eastern Interconnection’s energy use. These assumptions and the resulting generation and transmission needs drive design of a transmission overlay and underlying expansion that includes 10,000 miles of new extra high voltage (EHV) transmission at an estimated cost of $50 billion … The 20% Wind Energy Scenario presumes construction of a transmission overlay with 15,000 miles of new EHV transmission at an estimated cost of $80 billion. The new transmission would be a mix of transmission line sizes ranging from 345 kV to 765 kV for AC lines and up to 800 kV for DC lines. The majority of the conceptual overlay (approximately 75%) would be 765kV AC or 800kV DC. As in the Reference Scenario, the transmission overlay enables renewable and base load steam energy from the Midwest to reach a wider area and also has the potential to reduce energy costs to consumers along the Eastern Seaboard. Again, under the assumptions made in the JCSP’08, preliminary analysis indicates that this illustrative transmission overlay’s benefits may exceed its costs … > > … Although many new generation and transmission investments are moving forward, continuing uncertainties about the nation’s policies with respect to carbon regulation, renewable development policies, and super-regional cost and benefit allocation for projects that span multiple regions constrain other investments. More clarity about these policy issues will facilitate new bulk power system investments needed to turn infrastructure plans into reality and make inter-regional and interconnection-wide transmission expansion planning effective. So this much bottom line we have predicted: $50 billion for infrastructure to get to 5% wind and $80 billion for the infrastructure to get to 20%. Both likely cost effective over the long haul without accounting for the carbon cost or for the probability of it solving the possible intermittency issue but it _is_ a lot of money. And investments will not be made while the various players are unsure of what long term policies will be.