EVs and FCAS - what's future possible?

(This article uses the terms FCAS - Frequency Control Ancillary Services - and PFR - Primary Frequency Response - interchangeably. Just think 'FCAS' whenever you see 'PFR'. Some discussions even use 'Primary Frequency Control'. FCAS is a local-market acronym, though the phenomena are broadly similar elsewhere despite occasional differences in service market design, where they exist, and measurement and verification requirements - or in short, 'what you need to do and what you need to do to get paid, if you can at all').

Being an Australian working internationally in V2G/V2x/VGI/PickYourAcronym with professional experience working for/with local energy utilities (mostly bringing VPP opportunities to market) makes for an interesting perspective in international dealings as:

• Despite the confluence of the energy and mobilities industries creating much possibility in vehicle-grid integration, few people have worked in both across the value chain from R&D through go-to-market, and
• Australia leads the world in per-capita DER penetration with mature, leading energy and services markets wherein DER can generate strong revenues.

The incumbent sentiment in Australia was that V2G is exciting from a value perspective if a ways off technically asides from people with Nissan LEAFs and one (currently) particularly-expensive EVSE. Things recently got a little more mainstream-spicy with AEMO releasing the draft 2024 Integrated System Plan and some draft, V2G-friendly revisions to grid relevant codes; V2G is entering mainstream consumer consciousness and is certainly industry-topical.

However the general sentiment in the region developing the standards we'll likely inherent (Europe) is that V2G is technically possible and much explored but value cases are a while off. Accordingly when travelling I'm often asked by people representing companies with V2G parts, systems, products and trials we'd quite love to have down here... what's it worth in market? How do we make money out of this?

Australia is presently world-leading in clarity (broad word) on monetisable V2G value potential and, by virtue of a number of factors, flexible trading revenues given V2G would be pretty bloody competitive down here at any rate. Most get that EVs have batteries that in many cases will be parked more often than not (commercial and autonomous vehicle value cases differ), and short-duration and high-value grid interactions are generally favourable. Accordingly - whilst PFR ancillary service delivery from EVs isn't a new thought - its gained significant traction globally the last 18 months or so.

So what's possible?

Basics and market needs (skip if you know it)

PFR - what we know here as fast and very fast Frequency Control Ancillary Services (FCAS) - are system security services arresting a mains frequency excursion given sudden, unexpected discrepancies in power system demand and supply. These excursions can require services that lower the grid frequency beyond the normal operating frequency band (e.g., too much wind energy kicked on all of a sudden) or (more often) that raise the grid frequency (e.g., usually because a significant power system element - a generator or transmission infrastructure - failed). These services for contingency events (there are also regulation services - smaller, continuous tweaks around the edges - generally less amenable to DER); within these primary services are autonomous, secondary services are commanded (e.g., over SCADA or similar) and tertiary services are market actions: think milliseconds, seconds and minutes respectively.

Generally, within PFR service markets:

• Quicker responses are generally more valuable as they arrest a slide in the inertia of a power system faster, and are generally proven to promote a need for lesser overall volume of response to a contingency event, and
• Assets are paid more the earlier they respond within whichever service they aim to provide.

Much of the world increasingly values quicker responses, particularly given a proliferation of assets well-suited to providing such responses (particularly ESS). Sub 1-second responses are desirable.

EV/PFR love 101

Markets globally have various rationale in using EVs for PFR:

• The marginal costs of getting EVs to do as much bests e.g., procuring utility-scale ESS to do similarly (particularly in monolithic markets with low energy prices, whilst big batteries will do PFR with ease their impact to consumer costs are highly visible in public discourse),
• Almost all power systems expect (or experience) increasing volatility and reduced system inertia given transitions to variable renewable energy,
• Some are interested to manage chronic power system behaviours, and
• Some seek to amend or incentivise regulation towards democratizing decentralisation of power system design through market reform.

Much of the merchant utility world would like it if EVs did PFR service delivery yesterday. Some market/power system operators have not indicated they'll pay for PFR though in many it's a revenue-generating opportunity.

Appropriately enlightened consumers everywhere would also like it generally given no other flexible trading opportunity comes close (yet) on value-to-impost. Whilst early, local V2G sentiment is somewhat mixed with concerns on how consumers or EV OEMs may feel about using their EVs beyond 'pure' charging, on a long enough timescale where effects on asset life minimise and quality of service outcomes maximise consumers are most likely to tend towards competitive outcomes; if PFR revenues maximise competitiveness, so be it: if it's charged when you need it and pays, you'll take the cash.

And CPOs absolutely love it. Depending on segment there's little-to-negligible impact on customer amenity; anything that generates value that can netted off energy costs is good for margins and competitiveness: public charging networks can't get profitable fast enough; PFR helps.

So let's clear up some misconceptions around this.

Misconception 1: No one is doing this anywhere because it's really new/world first/super techy/etc

EVs for PFR is one of the earliest promoted uses for V2G - over 20 years ago now and demonstrated many times since (even in Australia, whilst was important to build local industry familiarity though was far from being first of kind globally or the most complex or complete project to these ends - there's a ton of good work, research and the like dedicated to this much globally and IMO it all deserves reading - below is a very, very brief summary of what may be salient).

In a pre-commercialisation context there have even been projects where PFR has been implemented in public charging with market settlement and all it entails. Such projects have involved building or evolving a number of key components to make for a complete, end-to-end solution, e.g.:

• EV-to-EVSE comms - broadly/functionally available on CHAdeMO from 2014 and CCS (ISO 15118 DC and AC) for a few years now depending how deeply organisations wish to be involved (more later),
• EVSE-to-CMS comms - whilst OCPP 2.0.1 is the first release that supports much of what's enabling for PFR in ISO 15118 and OCPP 2.1 will be the first official release that supports V2G at core, OCPP is a framework - not (yet) a standard - which means it can be/has been extended to suit (e.g., OCPP 1.6 has been previously extended to support measurement and verification requirements for PFR in a production V2G environment). This means EVSEs and CMS need to support customisations for a workable system, but it's been done for this and more,
• A 'Hall Pass' on metrology - various geos/markets differ in PFR triggering and validation resolution, accuracy and sampling rates. Australia has strict (if recently relaxed for some DER) metrology requirements, some markets less so, some even run certification (the latter is less likely to be robust in an EV context where control and execution are necessarily interoperable across different EV/EVSE combinations). Much (not all) metrology used is utility-grade expensive and measured 'at the gate'; progress is helped where these barriers can reasonably be lowered,
• A means to trade - if seeking to monetise, which can (depending on prevailing market regulations) involve an aggregation platform, and
• An EVSE (or if AC, an OBC) capable of reacting to a frequency trigger (which may be external). This typically involves firmware so programmed. Whilst done before, getting it right is neither impossible nor trivial.

CCS and CHAdeMO can both be commanded to have an EV 'do PFR things', though are only one component of a necessary, working system. Later CCS standards can store/respond to frequency-Watt curves (for AC V2G); smart grid standards provide the same data for generic DER endpoints - device-autonomous approaches are no longer prototype efforts.

The space is much evolved from AC Propulsion's original work in the early 2000's, e.g., excellent work by Dreev that went public last year and had a gestation a few years prior, demonstrating excellent regulatory compliance across a very wide region and being an end-to-end complete project (i.e. able to demonstrate settlement also). There preceding projects that were less fully commercialised in nature possibly e.g., the Parker Project in Denmark was among the first demos in modern times (commenced 2016 and completed before similar work started here in Australia); Nissan Europe later had a commercial project running in Denmark; there are others - Nuvve's been quite notable in the space too, with more projects than this example alone).

Misconception 2: But PFR it really needs V2G

PFR really does not. Simply drop or raise load in response, same as any other service provider. The physics doesn't change with EVs as DER.

PFR in practice requires scale (typical minimum aggregation bid volumes of 1MW for DER apply in many markets, and can be higher in others) which V2G achieves with greater ease given the magnitudes of power state change possible. The way in which that scale is achieved tends to create more value per EV. Accordingly for the sake of generating maximum grid impact (and value) most projects of this nature focus on V2G capability: from a zero power state (where V1G cannot provide any value) this allows export; from a charging state it's worth more.

That last bit is important in a second way - V2G increases asset availability in being to do something constructive more of the time. Trade desks like stationary ESS for their >90% availability; on V2G however the value of any one DER in an aggregated service delivery bid is effectively diluted by reliable availability estimates which are intrinsically conservative in nature and (with respect to EVs) at present poorly understood for lack of scale.

V2G gives more value and trading certainty for less cars and is thus topical in a time when there are less cars. But at scale (or in demonstrations of life therein) turning it down or off works just fine too.

Misconception 3: Only in CHAdeMO; CCS is not ready

(This one often gets a workout.)

CHAdeMO has had DC export sorted as a protocol since 2014. Many V2x products to have come to market. CHAdeMO's bidirectional specification is relatively simple; an EVSE commands the EV what to do from a power perspective, the EV communicates what it can do and how it's going. It's all updated continuously at CAN bus rates.

CCS operates a bit differently; more detail defining EV and EVSE behaviours is exchanged, there's arguably better security also. The charge loop responses (the data exchanged throughout a connected session can afford more detail and better articulated performance targets, particularly with AC V2G. Finally, high-level communications under CCS (15118-2 and -20) are extensible: they can be added to, stretched, have custom bits added - all within scope of the standards involved. As long as both an EV and an EVSE support a given custom 'Version' then a charging sessions can utilise as much.

There is some truth in CCS not being ready. The AC Bidirectional Power Transfer taskforce recently completed suggested amendments for ISO 15118-20 (both Peter Kilby and I were members) allowing EVs to act as bidirectional DERs over AC - not trivial as whilst ISO 15118 might be international, grid connection and smart grid standards differ the world over and the taskforce's resultant work was to create an approach yielding consistent outcomes among all markets represented: important, as an approach that would e.g., obviate either a large EU market or North America at the expense of the other could create development and go-to-market scale challenges that ultimately impair customers in both (and beyond). Some EV OEMs see AC V2G as a 'holy grail' towards vertical integration of energy services through reduced access barriers, particularly given the marginal cost of a bidirectional OBC may be less than that of a DC V2G EVSE; others see it differently (e.g., the Chinese market prefers to do away with the OBC altogether, lower vehicle costs and complexity).

There's also some truth in this not really being an impediment to progress. It's possible to run AC V2G today on a custom version of ISO 15118-2 or -20, and indeed some trials have facilitated CCS V2G in this way. Whilst not base-version 'vanilla 15118 V2G', where specifications are known and base version support is also included it can reasonably be made interoperable. Similarly, it's also possible to have developed DC V2G on a custom version of ISO 15118-2 (you'd likely not commence a development effort like this today as -20 now exists as a published standard, and works fine). Insofar as a PFR context DC V2G relies on the inverter being told what to do; and control functionality certainly exists (see 'dynamic mode') within CCS to give conceptual parity to CHAdeMO in ancillary service delivery (in practice there are differences though to cut a deeply technical discussion short, PFR on DC V2G is likely to be comparably competitive on CHAdeMO or CCS and the abilities to do either have existed a good while now). Obviously CCS DC V2G hardware is thin on the ground today as the relevant standard was only recently finalised; this doesn't mean relevant hardware doesn't exist or that groups wanting to trial or commit to pre-commercialisation efforts could not (or could not have) run V2G on CCS. It's been done before.

So CCS affords some particularly novel ways of implementing PFR over AC V2G, is plenty competitive on DC, is secure, and could be brought to market in either with enough will. Finalisation of standards and the emergence of production-grade products will help things, though first movers won't/shouldn't wait so long.

(And FWIW CCS is our future; CHAdeMO is practically deprecated in our market, with the only vehicles able to serve V2G from it being generations-removed from current technology enabling and determining key performance aspects of V2G. Nissan LEAF data isn't a reference point moving forwards; hasn't been for years, and a lot has happened in the last few years. Trialling PFR or whatever else with a LEAF is a bit like app testing on a Blackberry.)

Misconception 4: EVs will do all PFR, cash for everyone!

Participating ESS and other DER have had a great run on fast FCAS.

So then, EVs? They'll likely have more available power under many charging scenarios, however revenue magnitudes are scaled to speed of response, and (broadly speaking) the entire value chain of systems involved in vehicle charging is not yet optimised for this application (not technically, not culturally, not yet as an application - they're a part-interoperable and usually-part-third-party-integrated value chain across pack, BMS, OBC, EVCC, SECC, EVSE, metrology - that's before we get to enabling integration platforms that might command and trade the relevant functionality). Remember that unless operating on closed telematics and out of standards, in general an EVSE asks something of an EV, and then the EV determines whether or not that's possible, and responds (or not) accordingly. A charging EV may have a few checks and balances to go through before power starts flowing the other way (which are not in any way standardised nor optimised for speed); in some cases state of charge may not permit the power change required (e.g., a battery near minimum SoC will not be permitted, at least in a CCS scenario, to discharge). It's currently difficult to have EVs respond respond consistently in under 1 second (within heterogeneous fleets; a bunch of commercial EVs sitting at full charge in parking lot with a quiescent and intelligently-managed charge/discharge load on them may trade like a proverbial cash register at the right time - though this won't be all EVs everywhere),

For perspective a competitive stationary ESS might initiate response to a frequency excursion within 200-300ms; if configured to work as a virtual machine it might do so in a few mains cycles (tens of ms). They're products engineered in vertically-integrated spaces to specifically perform optimally in this scenario as relevant asset owners rely on that performance as a revenue source.

EVs are different with performance that dilutes potential value, which is again diluted by aforementioned availability challenges. To be clear: despite higher power than many consumer DERs, EVs may offer intrinsically lower-value PFR services needing to be further diluted given availability in aggregated bid volumes (time-dependent at that) or otherwise bid among diverse asset fleets. The net effect of the above would be diminished potential per-unit value, which puts downwards pressure on service enablement costs if to remain viable at all. Understanding here is critical for proliferation: despite regulatory evolution to towards reduced access costs the DER industry has broadly struggled here. That a thing (EVs for FCAS in this instance) is technically possible does not automagically make it a good deal if revenues are low and costs are high.

This being said there's some good amounts of innovation in the wild appearing too e.g., FCA, Engine and Terna have put together a trial involving 25MW of EVs (a relatively homogenoue fleet concerning vehicle types and usage profiles) and stationary ESS; it could be possible with very specific dispatch in the EVs or through cooperative dispatch of stationary and mobile batteries to create PFR service delivery that's fundamentally quicker off the mark. Terna are quick to point out that utility revenues generated are within the order of charging costs, which raises interesting questions - some are less technical in nature and more on optimising value sharing and cost reduction.

Finally it's worth remembering that Australia is now home to a number of utility-scale ESS - quite a few now, for which PFR is profitable. Not all other markets do. EVs will need to compete with these (very significant) investments despite possibly costing consumers less if used in similar contexts; if proven, there are salient policy questions to answer - in future would/should policy suggest we need these be replaced in whole or part with services acquired from distributed vehicles? 20M registered vehicles give or take, if 5% were parked at any one time all the time and able to move 5kW... such conservative numbers give 5GW at lower cost and due pause for future policy considerations. This doesn't obviate the bottom line needing to (broadly) get more competitive, just that there may be good future policy reason to reassess the top line too.

Misconception 5: One meter at the gate will do, this isn't an EVSE-level thing

Going to let this one slide for detail as there's a lot of work ongoing in EVSE metrology both globally and in Australia as is, and Ross De Rango recently wrote a pretty solid article that's worth your reading here.

This said my quick take is:

• EV owner/operators will, under many circumstances, want to be specifically reimbursed on what grid interactions they might opt into (so individual contributions will need to be identified),
• Once specified as to performance, PFR metrology isn't that hard, and
• DER PFR only gets ridiculous in practice when there's such a laser-focus on revenue metering that having the same infrastructure do PFR gets treated as an afterthought.

We still live in an age where many industry stakeholders haven't quite grasped that the 10th most important thing for the proliferation of flexibly-traded DER is 'security', and the remaining 9 of the top 10 is 'cost' repeated 9 times for effect.

(^^Seriously. If it's not a good deal for consumers, there's nothing to see here or on any please-flex-trade-consumer-DER-for-consumer-benefit-related topic. Discrete PFR metrology costs money to supply and install and is traditionally complex to manage for service delivery stakeholders. We're still not landed on best practice here in Australia.)

EVs can do PFR. It's designed into modern comms standards (ISO 15118). Per-charge-session, cost-competitive, integrated-with-revenue-metering-requirements metrology is a gap to close. Regulation to lower access barriers only gets us so far, or otherwise impairs value.

What's Tesla up to?

Tesla remains the only ESS solutions firm that supports virtual inertia and has a leading EV business and which makes it's own stationary and vehicular power system control and conversion solutions and which has a leading utility bidding solution and which is going into retail energy in various markets and which is a regulatory tour de force in most markets they've presence in (and the rest of it...)

There's talk of V2G on all models by 2025 though not much detail today on how that'll happen.

Today there's Cybertruck (V2L + DC export much like the F150 Lightning, albeit at higher power and into a neater Powerwall 3). This already should, in theory, allow PFR service delivery possibility from 2 sources one of which should respond a good bit faster than an EV. Accordingly this gives a Tesla 'system' (no word yet whether grid sync is enabled) the ability to respond quickly, though the merits of sharing a response across a stationary ESS and an EV are dubious when the power and/or network interfaces are constrained.

Enabling as much at Supercharger locations would possibly be more flexible and immediate, and could allow Tesla to lower costs to serve as an eMSP, particularly in markets where DER ancillary service aggregation is possible. There are many ways to technically integrate this and, given Tesla's vertical integration and domain expertise across the value chain, there are many opportunities to innovate. Tesla could leverage its strong experience in ESS PFR delivery.

Cybertruck also supports vehicle-to-vehicle charging. If (if) this worked with not-just-Teslas it could infer that possibly/maybe the Cybertruck may support high-level CCS communications (or that their own, indigenous methods may proliferate through other OEMs). Whilst (certainly) not guaranteed, it could imply a few interesting possibilities:

• That Tesla could integrate a range of vehicles - not solely their own - with their storage solutions/DER endpoints/etc and whatever businesses (e.g., retail energy) come of that (not necessarily a bad idea, as standing up a compelling energy business to rival Tesla in any market from a vehicle OEM perspective is a simply massive shift on all levels - it may be better to simply work with them), and
• That Tesla could create a version (or versions) of ISO 15118 with extended features that may contribute to lowering access barriers to PFR delivery, which may be supported (immediately or in time) by more than just Teslas. Others could do this too.

See below.

There's innovation yet to be had in comms for PFR

That last point is important. The current paradigm with CCS high-level communications is that the EV is asked what to do, it determines and delivers what it can do, and that revenue metering is done externally (there are system design reasons for this which are robust and best described elsewhere).

This is colloquially best described as a PITA for PFR service delivery for AC V2G, not least as the number of actors involved in needing to understand delivery of a very fast and particular service is >1, which historically constrains access and quality of outcome. There is, however, the possibility to evolve high-level vehicle comms and vehicle-side firmware to a point where EVs could be simply told do 'do PFR' (rather than how) and provide all that is required to play in market by way of a result.

Think about it:

• There's sufficient metrology in a vehicle to deduce when line frequency has slid to levels a response is needed - RoCoF methods are quite robust and are used extensively in many devices necessitating a freq-Watt response PFR delivery and settlement rules (no need to install utility-grade metrology in vehicles),
• Comms (e.g., an ISO 15118 version) could be amended to effectively command and run 'FCAS as an application' on-vehicle, setting service delivery market triggering and response requirements and then buffering and providing all information needed to complete market settlement,

• Some regulatory flex may be required to permit on-vehicle metrology to work in this context (though Tesla's been here before with MASS v6), and if some regulatory acceptance were provided allowing PFR delivery to be measured at the DER and not 'the gate' then this'd be the only metrology required, and
• Some OCPP development would be required to take that data beyond the EVSE to a CMS that can make use of it with an ISO, though this has also been done before.

The end result being that a CMS would ask a compliant EV to simply get involved or not, and in return the CMS would receive all it needed to get paid from the market ISO on a per-EV basis from the EVs involved directly: no need to learn how to make FCAS sausages, and no need to get squeamish watching them being made.

Where an EV were already able to provide AC V2G such functionality may be able to be delivered as an OTA firmware upgrade, and if an actor doing so had significant deployments in market already and a means to monetise as much (e.g., an appropriate aggregation and retail business per e.g., Tesla's intent) then such a solution could create very significant market distortion in a short space of time.

There's certainly many 'ifs' in the above section though one may conclude from the above, at the very least, that some regulatory movement and role consolidation across what's required to trigger, deliver, monetise and share value will go a long way towards realising what's possible here, and that such efforts may more directly lead to EV designs that are intrinsically more performative in PFR service delivery. These are strategic intents; an EV released today was (generally) sourced in pieces 2+ years ago from a supplier base aggressively building to cost on defined industry needs. A vendor like Tesla could redefine these priorities to better suit PFR delivery and create an appropriate, competitive template in market across OEM, supplier and service provider stakeholders.

Tesla isn't the only actor so capable; they're simply the most prominent in our market and some others today. This may change.

Appreciably there's a looming VHS-vs-Betamax question over whether AC or DC V2G is future-best; I'd suggest that both have technical merits however the ease with which either can deliver enduring consumer value will likely prove instrumental in ultimate success.

Conclusions

PFR from EVs is not new but is certainly growing in prominence and relevance as a leading application among grid-connected EVs in addition to serving system security requirements for many power systems. EV powertrains, EV charging systems and EVSEs are not yet broadly optimised for PFR service delivery in ways that increase access and service delivery competitiveness. Solutions, standards and frameworks in the space are rapidly growing in technical completeness yet there exists significant innovation scope that may improve performance and lower access barriers in future. Potential exists for leading organisations vertically integrating across a number of disparate stakeholder roles to innovate quickly towards solutions in market with heightened technical and value-generating performance.