VC09 Grid integration and system value
Depth of coverage
At its target depth of L3. What the depth levels mean.
What this layer covers
Dispatchability, firmness, capacity value, balancing, curtailment, the comparator basket, offtake and market position
Where it ends
Value to the power system, not the cost of the plant, which is XC02
Deep area
This layer is studied in more depth than most. It belongs to the deep area Power electronics and ground segment.
Grid integration and system value
Cost alone does not show what a power plant is worth to the grid. The International Energy Agency and the firm Lazard each say that plain levelised cost, the lifetime cost per unit of electricity, misses system value (CLM-0301, CLM-0303). Two 2025 studies model what a space plant would add to a future energy system (CLM-0286, CLM-1172). In one, a space plant would lower total system cost only at the more favourable of NASA's cost projections (CLM-0286). For Great Britain, the system operator states that at a system inertia of 102 GVA.s, a sudden loss of at least 2,000 MW of supply would pull grid frequency down to 48.8 Hz, where disconnecting customers begins. That threshold would change with the response services held (CLM-0795). Inertia is the energy stored in spinning machines that steadies grid frequency. That report does not discuss space solar power. An index count made for these records on 4 September 2026 found 2,551 papers on space solar power. None has a title or abstract that mentions grid codes, though many older papers in the index have no abstract (CLM-0799). A third 2025 study reports better voltage stability, but its orbiting mirrors light an ordinary solar farm in a nine-bus test network, with steady-state calculations only (CLM-0800).
Two 2025 studies model what a space plant would add to a future energy system (CLM-0286, CLM-1172). In one, a space plant would lower total system cost only at the more favourable of NASA's cost projections (CLM-0286). No cited source tests such a plant against the grid's connection rules (CLM-0780, CLM-0799). Cost measures alone miss a plant's value to the grid (CLM-0301, CLM-0303).
Scope. What a space plant's power is worth to the grid once it arrives. Steady output, power that can be sent where it is needed (dispatch), and a fit with the connection rules all add value. This section also covers who would buy the power. Plant cost and the connection equipment are covered separately.
What is settled. Levelised cost (LCOE) is lifetime cost divided by lifetime output. The International Energy Agency (IEA) and the OECD Nuclear Energy Agency say it lacks the value a plant gives the system (CLM-0301). Lazard, a financial advisory firm, says its figures leave out intermittency and total system cost (CLM-0303). The IEA built an adjusted measure, VALCOE, a value-adjusted levelised cost, that adds credit for energy, capacity and flexibility. Its result depends on the share of variable renewables and on the cost of storage, and its model ignores grid bottlenecks (CLM-0308). See Comparing solar and firm power on cost for the full argument.
Grid documents give the scale a large plant must fit. In Great Britain the security standard caps the loss from a fault on one generation circuit at 1,800 MW (CLM-0780). Inertia is the energy stored in spinning machines that steadies grid frequency. In 2025 the system operator proposed lowering its minimum inertia from 120 to 102 GVA.s (gigavolt-ampere seconds), subject to a decision by Ofgem, the energy regulator. That floor is sized to survive a largest loss of 1,800 MW, a planning figure tied to specific nuclear units (CLM-0793). At 102 GVA.s, a sudden loss of at least 2,000 MW of supply would pull grid frequency down to 48.8 Hz, where disconnecting customers begins. That threshold would change with the response services held (CLM-0795). The report does not discuss space solar power. It shows only that a 2 GW loss at one point sits at the edge of the events Britain plans for (CLM-0795). It does not show that a satellite plant would cause disconnection. The operator also says a 2 GW coal station would roughly have supplied over 6,500 MVA (megavolt-amperes) of short-circuit support, the grid's strength to hold voltage in a fault. No cited source says what a receiving station would supply (CLM-0796).
On dispatch, a 2017 patent claims beam steering through 360 degrees in azimuth (around the antenna's axis) and about 55 degrees either side in elevation (tilt away from that axis) (CLM-0900). From geostationary orbit, where a satellite stays over one spot on the equator, Earth has an angular radius of about 8.7 degrees. So, on the patent's claim, the antenna would not limit where on the visible Earth power can go. A receiving station at the target, the elevation angle there and the state's licence would (CLM-0900). No cited source says how fast the beam could be moved (CLM-0900).
What is disputed or uncertain. The favourable evidence is thin. One 2025 conference paper models orbiting solar reflectors in a nine-bus test network. It reports lower fuel cost, lower emissions and better voltage stability. It uses steady-state calculations only, and its concept ends in an ordinary solar farm, not a rectenna (CLM-0800). Two other 2025 studies put a space plant into a model of a whole power or energy system. In a model of Europe's power system, one design would cut total cost by 7 to 15 per cent, but only at the more favourable of NASA's 2050 cost projections (CLM-0286). A UK feasibility study's model gives a small 52 MW system a benefit of about GBP 23 million a year in southern England in 2040 (CLM-1172).
The unfavourable evidence is also indirect, chiefly the 2,000 MW threshold (CLM-0795). A search of a research index made for these records on 4 September 2026 found 2,551 papers on space solar power and none whose title or abstract mentions grid codes, reactive power or grid forming. Many older papers in the index have no abstract, so this does not show that no study exists (CLM-0799).
A 2010 paper argues that space solar power is "already comparable" in cost to ground solar and wind backed by storage. It gives two prices for the same 26 GWh of storage, about USD 650 million and about USD 5 billion, without explaining the gap. The comparison uses the larger figure. Storage is a small part of the total cost, so by this site's own arithmetic the smaller figure would narrow the margin but not change the paper's verdict (CLM-0198). Geomagnetic storms of class G3 (strong) and above, on the scale of the US National Oceanic and Atmospheric Administration (NOAA), occur on about 12 to 18 days a year averaged over a solar cycle. No cited source says how much they would weaken a beam, and so its firmness (CLM-0118 (low confidence)).
On the market side, on 30 September 2026 Virtus Solis and Brae Systems, which says it will use the power for undersea data centres (CLM-1213), announced a 20-year power purchase agreement, a contract to buy a plant's output. It covers 100 MW from orbit, received in Illinois, with an option to expand to 250 MW. Only the two companies have said so, and no price or start date is given (CLM-1212). Virtus Solis calls it the first "in a series of commercial offtake agreements" over the next several months but names no further buyers (CLM-1216 (low confidence)).
What is missing. No cited source tests the firmness of a space plant, its ability to supply power on demand. The European model takes each design's output from NASA's figures (CLM-0286). The UK study's two sites are model inputs, not a siting study (CLM-1172). The reflector paper uses steady-state calculations only, with no study of faults (CLM-0800). No cited source assesses a gigawatt-scale receiving station against the connection rules (CLM-0780, CLM-0799).
Read next. Can a 2 GW receiver connect to the Great Britain grid at one point (CLM-0795)? Which assumption drives the cost spread. Comparing solar and firm power on cost. Getting the power into the grid. What it would cost.
Records
67 of the 65 records tagged to this layer are published. The rest are not yet published. A record is published only after a second reader has checked it and it has passed every publication check. What the gate checks.
| Record | In plain language | Tier | Confidence |
|---|---|---|---|
| CLM-0118 | Storms big enough to disturb the ionosphere over the UK happen on roughly 12 to 18 days a year on average, mostly around solar maximum. Which figure is right is not yet known. | T3 | LOW |
| CLM-0198 | The same 2010 paper gives two very different price tags, about $650 million and about $5 billion, for storing the same amount of electricity (26 gigawatt-hours, about one day's supply for a city the size of Austin, Texas). The paper does not explain why the two numbers differ. | T5 | HIGH |
| CLM-0301 | The IEA itself says plain LCOE misses how useful a power plant is to the wider electricity system, which is why it built a second, add-on metric. | T3 | HIGH |
| CLM-0302 | The US government's own energy statistics agency warns that comparing plain LCOE across different kinds of power plant, without also looking at value, can be misleading. | T3 | HIGH |
| CLM-0303 | A major financial advisory firm's own widely-used LCOE report says plainly that its numbers do not cover intermittency or total system cost. | T4 | HIGH |
| CLM-0307 | The US government's avoided-cost metric shows that, for the power plants it expects to be built, value and cost are within about 25 percent of each other; for some plants it does not expect to be built, such as offshore wind, coal and nuclear, value is half of cost or less. | T3 | HIGH |
| CLM-0308 | The IEA's alternative metric adds credit for how much a power plant helps keep the grid reliable, on top of its raw energy cost, but the IEA itself says the answer depends heavily on what the future electricity system is assumed to look like. | T3 | MED |
| CLM-0309 | One influential academic paper shows that once you add in the extra cost a variable power source creates for the rest of the grid, its true cost to the system can end up roughly double its own sticker price at high market share. | T2 | HIGH |
| CLM-0310 | How much a solar farm can be relied on to replace a conventional power plant, measured properly, drops sharply as more solar is added to the same grid. | T2 | HIGH |
| CLM-0311 | As more wind or solar power is added to a grid, each additional unit of it earns a lower price on average, because it increasingly arrives when everyone else is also generating. | T2 | HIGH |
| CLM-0312 | A major financial advisory firm has estimated, using US grid operators' own published figures, what it adds to the cost of wind or solar to count them as dependable capacity alongside gas power stations; on its figures the addition is between about 8% and 85% of the plant's own cost, not many times more. | T4 | HIGH |
| CLM-0318 | Looking across every different way economists and grid operators actually measure how much extra a reliable power source is worth, it is worth a bit more: up to about four times as much when measured as an average across a grid's solar farms, which stays well short of the 12-to-80-times difference space solar power's own cost study found. Measured as the value of the last solar farm added to a grid already full of solar, it can be much larger, and the study behind that figure gives no upper limit. | T0 | MED |
| CLM-0319 | The register's recommended way to check space solar power's economics against something other than plain cost-per-unit is the IEA's value-adjusted cost, whose formula is now public, checked against a US value-for-money ratio whose underlying figures are published, plus a comparison against an illustrative cost of firm, reliable power in today's electricity markets. | T0 | MED |
| CLM-0401 | A 2004 review calculated that, under some of the most extreme conditions measured during a large solar storm in October 2003, only just over four fifths of a microwave power beam would get through the ionosphere and atmosphere to the ground, against more than 99.7 per cent normally. The storm lasted more than a day, but conditions varied, so a loss that large probably (our inference) did not last throughout. The standard 1978 efficiency figures include no allowance for it. | T3 | MED |
| CLM-0757 | In its own report on the February 2022 attack, Viasat says the attacker got in through a misconfigured VPN device, reached the network management system, and then sent the network's own ordinary management commands to tens of thousands of customer modems at once, wiping enough of their memory to knock them off the network without permanently breaking them. | T4 | HIGH |
| CLM-0758 | Viasat's own report, about five weeks after the attack, says it had found no evidence that the satellite itself or its main ground stations were directly involved, and that its analysis of affected modems found no impact on their physical or electronic parts and no evidence of tampering with modem software or firmware images, yet the service still went down across much of Europe. | T4 | HIGH |
| CLM-0762 | The civil space command-link security standard says exactly which parts of a message it protects and which it does not: it fully protects the command payload, only partly protects the message header, and leaves several control and status channels unprotected altogether. | T1 | HIGH |
| CLM-0763 | The civil space link security standards deliberately do not say which encryption to use, do not describe how to build a real system, and leave the choice of algorithm to the mission; a companion document adds the key management, rekeying and replay protection needed to run the protocol. | T1 | HIGH |
| CLM-0780 | The UK rules for connecting power stations set a hard limit on how much generation one fault may disconnect at once: 1800 MW for a fault on the station's own connection, and nothing at all for a fault on a single transmission line. | T1 | HIGH |
| CLM-0790 | Great Britain does not oblige an inverter-based generator to behave like a synchronous machine; it pays for that behaviour through a market. Plants that do offer it face a demanding specification, including being able to keep operating when the grid at its connection point has a short-circuit level of zero. | T3 | HIGH |
| CLM-0791 | In 2024 the EU was moving towards putting grid-forming behaviour into its connection code, following a December 2023 recommendation, but the draft wording required it only where the national system operator asks for it. Britain and Australia already had their own versions. | T3 | HIGH |
| CLM-0793 | Britain's system operator plans to run the grid with less spinning inertia, and it sets that limit from the size of the biggest single generator loss it must survive, currently 1800 megawatts. | T3 | HIGH |
| CLM-0795 | Britain's system operator says that at the lower inertia level it is moving to, losing 2000 megawatts at once would be enough to start disconnecting customers, and losing 3.3 gigawatts at once could cause a nationwide blackout. | T3 | HIGH |
| CLM-0796 | Britain's system operator says its grid needs both spinning inertia and short-circuit strength, and gives a scale: a single 2 gigawatt coal station used to supply over 6,500 megavolt-amperes of that strength. | T3 | HIGH |
| CLM-0799 | A search of a large research index on 4 September 2026 found 2551 papers on space-based solar power and not one whose title or summary mentions grid codes, fault ride-through, reactive power, harmonic distortion, grid-forming or power quality. | T0 | MED |
| CLM-0800 | A 2025 power-engineering paper does model space-derived solar power inside an electricity network, but it uses a nine-bus textbook test system and only steady-state calculations, so it does not test any of the connection rules a real plant would have to meet. | T2 | HIGH |
| CLM-0895 | Twice a year, for about six weeks around each equinox, a satellite in geostationary orbit passes through the Earth's shadow once a night, for up to about seventy minutes. Keeping two gigawatts flowing through that would need roughly two and a third gigawatt-hours of batteries. The 1978 design carried about a two-hundredth of that, and only to keep its transmitter tubes warm. Over a year the shadow costs about one per cent of the time. | T0 | HIGH |
| CLM-0900 | The satellite can point its beam far further than there is Earth to point at, so moving power from one receiving station to another is not limited by the antenna. It is limited by other things, including whether a receiving station has been built there and whether that country has allowed it. | T3 | HIGH |
| CLM-1109 | The rulebook says the same as the guidance: nobody has to make their inverters behave like a rotating machine, but the grid needs enough plants that do, and it pays for them. If a plant offers it, it must be able to run into a dead network, feed its full rated current into a short circuit for the fault-clearing time, and be tuned within a stated damping range. | T1 | HIGH |
| CLM-1210 | Britain's grid runs at 50 Hz, normally kept between 49.5 and 50.5 Hz. A power station connected to it, which would include a rectenna, must keep running between 49 and 51 Hz without limit, and for set minimum times further out, down to 47 Hz and up to 52 Hz. | T1 | HIGH |
| CLM-1212 | A space solar start-up says it has signed a 20-year deal to sell power from orbit to a data-centre company: 100 MW at first, perhaps 250 MW later, received in Illinois. Only the two companies have said so, and no price or start date is given. | T6 | MED |
| CLM-1213 | The first buyer wants the power for underwater computer centres for AI. The release pitches power from orbit as a fix for AI's power and cooling limits. | T6 | MED |
| CLM-1215 | The deal was announced on the day of a space solar session in Washington, D.C., where the company says its chief executive will speak. | T6 | MED |
| CLM-1216 | The company says more customers are lined up. It names none and gives no numbers. | T6 | LOW |
| CLM-1224 | A UK space solar start-up said in 2024 that it had a deal to supply an Icelandic utility with 30 MW from orbit by 2030. | T6 | MED |
| CLM-1226 | In April 2026 Meta said it had reserved up to 1 GW of future space solar power from Overview Energy, with a test in 2028 and power possibly from 2030. | T6 | MED |
| CLM-1231 | In 2009 a California utility agreed to buy 200 MW from a space solar company by 2016. No held source records what became of it. | T5 | MED |
| CLM-1260 | In 2009-2011 California's regulators took a contract to buy power from a space solar company through each formal step: the energy commission accepted a 200 MW space solar receiving station as a renewable source in principle, and the utility regulator signed off on the contract's emissions terms. None of these papers shows the satellite or the station being built. | T3 | HIGH |
| CLM-1261 | In 2009 California's largest utility signed a deal to buy up to 200 megawatts of power from a space solar company for 15 years, starting in June 2016, from a receiving station in central California. It agreed to pay more than the usual benchmark price, and the details were kept confidential. | T3 | HIGH |
| CLM-1264 | The plan had three steps. First, check whether space solar makes sense against ground solar, what the law allows, and whether it could power Mars missions. Second, compare system designs and pick up to three. Third, study two or three small demonstration missions in enough detail for ESA to decide whether to go ahead. | T3 | HIGH |
| CLM-1380 | NOAA's storm levels G1 to G5 correspond to the Kp disturbance index reaching 5, 6, 7, 8 and 9. | T3 | HIGH |
| CLM-1381 | NOAA's own table confirms the storm-day counts the register was using: about 130 strong, 60 severe and 4 extreme storm days in an average 11-year cycle. | T3 | MED |
| CLM-1419 | The Royal Society worked out that a British power system running only on wind and sun, with stored hydrogen to cover calm and dark spells, could supply electricity in 2050 at an average of 52 to 92 pounds per megawatt-hour in 2021 money. Most of that cost is the wind and solar power itself. | T3 | MED |
| CLM-1420 | In the Royal Society's model, only about 15 per cent of Britain's electricity in 2050 comes out of storage, so the price of storage moves the average cost little. Each unit that does come out of storage costs many times more than wind or solar power used straight away. | T3 | MED |
| CLM-1421 | A 2016 Imperial College study run jointly with three renewable-energy companies found that adding wind to Britain's grid in 2030 would bring extra system costs of about 5 to 9 pounds for each megawatt-hour the wind farms produce, compared with adding nuclear, if the grid has a fair amount of storage and other flexibility. Most of that extra cost is back-up power stations for windless periods. | T4 | MED |
| CLM-1422 | Imperial College found that the extra system cost of wind and solar in Britain in 2030 depends heavily on how flexible the grid is: about 40 to 48 pounds per megawatt-hour of their output with no new storage or demand response, but about 5 to 17 pounds once those are added. The figures are measured against nuclear power, not counted from zero. | T4 | MED |
| CLM-1423 | The UK's climate advisers said in 2019 that fitting large amounts of wind and solar power into the grid adds roughly 10 to 25 pounds to each megawatt-hour they produce, when wind and solar supply up to about half to two-thirds of the year's electricity. They also said there is little UK evidence for shares above about a third. | T3 | MED |
| CLM-1424 | The UK's climate advisers broke the extra cost of wind and solar into parts: backup power for peak demand, wasted output and keeping spare plant running, and new power lines. They warned that the parts overlap, so they cannot simply be added up. | T3 | MED |
| CLM-1425 | The UK's climate advisers estimated that a nearly carbon-free power system in 2050 would cost about 4 billion pounds a year more than one built on gas, and that the cost of coping with changeable wind and sun is under a tenth of the total. | T3 | MED |
| CLM-1426 | The UK government estimated in 2020 that a wind or solar farm opening in 2030 brings wider grid costs, compared with a nuclear plant, of between about minus 5 and 17 pounds per megawatt-hour of its output, plus up to 13 pounds for transmission lines, depending on the farm type and on how the rest of the system is built. The figure grows for offshore wind built later. | T3 | MED |
| CLM-1427 | The UK government says its 2020 figures for the wider grid cost of each type of power station show how one small extra plant would change costs, compared with a nuclear plant. They are not the total cost of running a whole power system, and they change with the rest of the system. | T3 | MED |
| CLM-1428 | Britain's grid operator estimated that the cheaper of its two plans for a clean power grid in 2030 would cost about 126 pounds for each megawatt-hour used, in 2024 money, a little more than a plan that misses the climate targets, though NESO calls the costs of all the options similar within the bounds of uncertainty. It counts the capital cost of new plant and grid built since 2023, plus running, fuel and carbon costs, but not the capital cost of plant already built. | T3 | MED |
| CLM-1429 | A search on 13 October 2026 found no published model of Britain's power system that is free to decide how much space solar power to build. One British government study valued small space solar plants in a model by scaling down a much larger assumed plant; the only free-choice model found covers the whole of Europe. | T0 | MED |
| CLM-1430 | Put in 2024 money, a reliable British grid built on wind, sun and stored hydrogen would cost about 61 to 107 pounds per megawatt-hour in 2050. Set against the top of that range, the UK government's space solar study comes in at about half, and NASA's study, rebuilt in 2024 money, at nearly nine times. The two sides are costed differently, so this is a rough guide, not a like-for-like price comparison. | T0 | MED |
| CLM-1431 | In the first week of November 2024 the wind was light: wind made a tenth of Britain's electricity supply, against almost 30 per cent over the year, and gas made half. | T0 | HIGH |
| CLM-1435 | In NASA's design, rebuilt in 2024 money, cutting the launch price to a tenth while keeping everything else the same lowers the cost from about 930 to about 340 pounds per megawatt-hour. That is still about three times the top of the Royal Society's modelled 2050 cost range (about 61 to 107 pounds per megawatt-hour) for a British grid built on wind, sun and stored hydrogen. The UK government's study, for a mature fifth-built satellite, gives about 25 and 67 pounds per megawatt-hour for its low and high launch costs. The two sides are costed differently, so this is a rough guide, not a like-for-like price comparison. | T0 | MED |
| CLM-1436 | A UK study says that one space solar power system would typically deliver about 2 gigawatts to the grid, and it compares this with the output of a nuclear power station. | T4 | MED |
| CLM-1449 | Britain's solar panels make far less power in winter. In December 2024 they made about a ninth as much as in June. On the worst day of 2024, in late November, they made less than a seventieth of what they made on the best day, in early June. Even within December, the worst day gave about an eighth of the best. | T0 | HIGH |
| CLM-1469 | In the Royal Society's model of a British power system run on wind and sun in 2050, electricity fed into the grid costs about 1.7 to 2 times what the wind and solar power itself costs. At the cheap end, the electricity costs about 1.7 times what the wind and solar power itself costs. At the expensive end it costs about twice as much. | T3 | MED |
| CLM-1470 | Britain's capacity market does not count gas or nuclear power stations at their full size. It counts a gas plant at about 88 to 92 per cent of its capacity, and a nuclear plant at about 75 to 85 per cent. Government advisers say the nuclear figure now rests on too few plants to be reliable. | T3 | MED |
| CLM-1471 | Britain's nuclear power stations were not running at full output for much of the time. From 2012 to 2022, planned and unplanned shutdowns cost the older reactors about a fifth to a third of the electricity they could have made, and the newest, Sizewell B, about a seventh. | T3 | HIGH |
| CLM-1474 | One UK study designs small power satellites that beam to receivers in Scotland, Canada and Japan, switching between them as they move along their orbit. Each satellite beams to one receiver at a time, and the UK receiver comes first when both are in view. | T4 | MED |
| CLM-1475 | Some writers point out that a power satellite is not tied to one receiver: in principle it could beam to a different site, for example if a military base moved. No study held here tests this or uses it to cover a receiver that is out of action. | T3 | LOW |
| CLM-1476 | The European study states that it used a 3 per cent interest rate for the cost of the space solar satellites. It does not say, in the paper itself, what rate it used for wind, solar and the other power sources, so it is not possible to tell from the paper whether space solar was given an easier test than its rivals. | T2 | MED |
| CLM-1486 | A 1977 NASA study of how receiving stations would join the US power grid looked at two kinds of shadow. For about six weeks around each equinox, the Earth would shade each satellite once a night near midnight; the study judged this easy to cover, because demand then is about half its peak. If more than a hundred satellites were built, they would also shade each other each morning and evening, close to peak demand. By the study's table, that would cut the number of five-gigawatt receiving stations the US grids could take in 2025 from about 360 to about 60. The study added that direct-current links between the regional grids would largely remove the problem, but gave no figures for that. | T3 | MED |
| CLM-1487 | In Britain, the amount of fast back-up power kept ready depends mainly on the biggest single block of power that could be lost at once; the rules do not set it by fuel. So a space solar station would need about the same fast back-up as a gas power station whose biggest single loss is the same size. A 2 GW space plant would be a bigger single loss than the 1,800 MW Britain now plans for, if one fault could take all of it. A satellite in geostationary orbit also passes through the Earth's shadow each night for about six weeks around each spring and autumn equinox, for up to about 70 minutes. Those times can be predicted exactly, and other power stations would have to cover them. | T3 | MED |
| CLM-1488 | A Royal Society report on storing electricity in Britain, drawing on the Met Office, says a spell of very low winter wind lasting up to a week comes every few years, and a calm summer spell of up to four weeks once every ten years. But in its model of a 2050 grid run on wind and sun, the biggest drain on the store came in the weather of 2009 to 2011, a run of low-wind years. The report warns that studies of single years, or of only the worst spells, can badly underestimate how much storage is needed. | T3 | MED |