Commercial solar case study
Castle Eco Solutions case study: five commercial surveys with decision makers in three weeks
Dean Walmsley, MD of Castle Eco, switched to TNW after a rival took £5k and ghosted him since March. Five commercial surveys in three weeks, all with MDs or finance directors, now chasing a near 900kW job.

Watch the full interview with Castle Eco Solutions. This page summarises what they told us on camera.
Full interview transcript
Read the full transcript of the Castle Eco Solutions interview
Word for word from the video, with filler words such as “um” left out.
Dean, would you like to introduce yourself and talk a little bit about Castle Eco? Yeah. So my name's Dean Walmsley. I'm the MD of Castle Eco.
Done a lot of insulation and heat pumps solar, battery storage under government grants. But Labour decided to squash all that, so we've had to diversify. We do- We've got a company in Saudi Arabia that do solar as well, so we've just attacked solar. But doing it in a different country with the team we've got there and doing it here has been a bit of a different challenge.
So obviously the domestic market's quite tough because we're ... it's a bit of a race to the bottom. But you know- Yeah ... doing a bit of a mix with commercial and commercial and domestic kind of works. But we were really struggling to get decent commercial leads, how we get through the door. We've tried another company that kinda does L- LinkedIn outreach and email campaigns, and I think I paid them five grand, and I've never heard o- of them since.
Whereas you guys- ... we loaded a couple of grand on a card, and the leads started coming through within 10 minutes. I like how we just get to- Yeah ... to have a look at the jobs on WhatsApp first with all the detailed information and get to choose what kind of jobs suit us the best.
Yeah. And then y- we kinda pick the ones, you book them in. Great system for confirming the appointment, so then it were obviously, are these serious people when we get there? So we've landed, we've done five appointments. Finance directors or MDs at every single job, so straight through to the decision makers.
And the what, really, the closing side of things is our experience if, out of them five jobs, if I close two, I'll be absolutely over the moon. Some other more experienced installers might close all five. So it's not completely down to you guys. You've done your job. It's over to me now.
But the biggest interest- Yeah, no, I'm sure of that. Yeah. The biggest interest I've had is a a huge job. It's nearly 900 kilowatt job, but they've, ... and, they're quite serious about it. So yeah progressing nicely. Probably gonna have to buy- Brilliant
a few smaller ones if I'm attacking this big one. Yeah, no Yeah, for sure. Been good so far. I've had to actually, like I say, 'cause it speaks my time, 'cause I've had to shrink so much and start again, that you could be chucking me another 20 leads today, but I'm like whoa, let me just process." I'd rather be on that side of the fence than the other side where nothing's coming through at all, yeah. That's where we like to be. How long have you been working with us so far? Oh, three weeks. Yeah not long. Three weeks. Been to five appointments. Nice. That's good to hear. And in terms of the actual service itself, what do you think's been the most valuable part of it for you guys in particular?
Everyone wants exclusive leads, don't they? But I think even if you're pinging the same leads out to 10 WhatsApp groups, and it's the fastest finger first, isn't it? Oh, that suits me, put my thumb up. You earmark it for us, and it doesn't go to anyone else. So we are exclusive in that respect.
But not just the, leads aren't coming into a system where your appointments are set, and you have to go to all of them. Like a rush thing without getting all the information and actually choosing, ... Being able to handpick the leads that suits you is a real bonus. God, don't know- Yeah
probably 20 a day coming through on WhatsApp, and I'm like, "Ooh, that one." If I've got a busy week and wanna travel two and a half hours, there's always a couple that are only an half hour of me, which is good. Yeah. So yeah. We're learning. We're learning, you're helping 'cause you're taking a lot of that headache off me.
I'm landing with my drone, taking some drone footage, getting the pictures I need potentially for the DNO application and talking to the guy, asking him what he wants and what he's trying to achieve. And then, we're process- processing it. The actual ... If I were having to find them myself, Jesus crap Christ, yeah.
Just leave it to you guys. Love it. And in terms of, you mentioned a little bit about another company you've worked with. What's your sort of experience with other lead generators that you've worked with in the past? In the ECO scheme they were completely different. They were all rogues, to be honest.
But they were like, ... a lot of door knocking. The eligibility was very different. We're tackling the able to pay market here, so it's ... with other lead gens, this online, this global online lead generation firm that are, a- apparently in three countries and UK number one leading company, have literally ghosted me since March.
So yeah. So there's that. Then domestic lead generation coming through Facebook, they are hot leads, so it is what it is if you get back to them quick enough. But it's ... For commercial especially, like you guys have ... the proof's in the pudding, isn't it? It's, Yeah, no, I appreciate that Good system and then obviously you mentioned that they ghosted you, and did they provide anything at all or?
I've been that busy going out on your surveys, I haven't had time to complain properly. So I've let, left them to it. But the responsiveness over email, terrible. It's- Yeah ... I'm getting through to different people. Like you guys, on WhatsApp and, you're a busy man, but you answer every WhatsApp- Yeah
every question we have. You've always got someone there to, to- Yeah ... to assist you if you need. That's, that, that's the top priority for me. I've got two, two lead assigners in the chat, so you can get a hold of any two of them at one time. I've also got a manager as well that you can call, and then also me.
I like to respond within five minutes, like any time of the day. Yeah ... and that's, I think that's the most important thing. There's nothing worse than slow communication. Do you know what I mean? It's just like- ... it's just a respect thing, in my opinion. Yeah ... but yeah, no, I appreciate that a lot.
And in terms of the sort of average deal size that we've been bringing you, what... Like, where does that sort of land? I'm picking them, aren't I? So y- I went to the, this big one, even though I think it's a little bit too big for me to be my first one. And just because it were round the corner from me.
It were round the corner. It were, I think, 25 minutes from my office. And then some of the smaller ones, I went to Wales, which were getting a renovated pub, which will... They want a load of solar panels on a flat roof. That would've been a quick turnaround job. But it's them who weren't ready for it, plus it's a listed building.
But it's a modern flat roof extension. And it's out of sight from the road, so they probably will get planning, but it's for the customer to go through that malarkey first. Yeah ... and yeah, and then there were a couple of, I think, there were a couple of 50 kilowatts, a couple of 100 kilowatts, and then a few big ones as well, yeah.
A few- Nice ... perfect. And then in terms of the volume of
leads how's that been? Yeah. That's... Yeah, I've had to, I've had to thumbs down to a lot of them that I probably- ... couldn't take just because I I've just because we're in a, in the early days. I've been to five appointments. I'm processing them through. I'm doing the designs. I'm talking to the customers.
I'm out getting things quoted for them, as well as getting me domestic stuff going. So obviously yeah, I could've took, I could've been on a, on 10, 20, 30 appointments in the last three weeks, ... getting those done. Yeah. Perfect. Yeah. And would you say that a sort of performance-based approach like we have where, you only pay for an attended survey, that sort of thing, is actually gonna be viable?
Would you say that's a scalable model for you guys? Absolutely. Yeah. Yeah. Yeah. Again, the better we get at the con- converting them and processing them. I think there were only one out of the five where the finance director's a little bit busy to get me the half-hourly data.
He's under pressure in his own work, so but it's one out of five. The re- the other four were very serious, and I'm sure he is serious. He just has to empty his own plate, doesn't he? So- Yeah. But yeah. It's, ... No it's brilliant. It's, if they cancel for any reason, you obviously replace that, don't you?
100%. Yeah, no, I appreciate that a lot. And one final question. I always ask it, but but many people are hesitant. Would you recommend us to other companies who are looking to get more work? Yeah. Absolutely. In France, you mean? In France? Yeah. Yeah. No. Yeah. I always ask you the question. They're like, "Oh, what?
In my area, though?" Yeah. There's a lot of solar installers around me- ... so keep it quiet. Yeah, no, I appreciate that a lot, mate. Cheers.
- Interviewee
- Dean Walmsley, managing director
- With TNW at interview
- Three weeks
- Surveys attended
- Five, each with an MD or finance director
- Site sizes
- A mix of around 50kW, 100kW and larger sites
Who Castle Eco Solutions are
Dean Walmsley is MD of Castle Eco Solutions. The business previously did insulation, heat pumps, solar and battery storage under government grant schemes, and when those were cut it diversified. It also has a company doing solar in Saudi Arabia.
The situation
With the domestic market a race to the bottom, Castle Eco wanted a mix of commercial and domestic work, but it was struggling to get decent commercial leads. Dean had paid another company that does outreach and email campaigns around £5,000 and says he had not heard from it since March.
What TNW delivered
Dean loaded a couple of thousand pounds onto a card and leads started coming through within ten minutes. Jobs are posted on WhatsApp with full detail first, and he chooses the ones that suit; once he gives a lead the thumbs up it is earmarked for him and does not go to anyone else. He says around 20 a day come through, and there are always a couple within half an hour of his base.
Appointments are confirmed before he travels, so the people he meets are serious. On site he takes drone footage and the pictures he may need for the DNO application, then designs and quotes.
The sites have ranged from a couple of 50kW jobs and a couple of around 100kW up to larger projects. The biggest, nearly 900kW, is about 25 minutes from Dean's office. Another was a renovated pub in Wales that wanted panels on a modern flat-roof extension of a listed building, out of sight from the road, which needed the customer to deal with planning first. Dean is candid that closing is down to his own team: if he closes two of the first five he will be delighted.
Four of the first five prospects were very serious; the fifth, a finance director, was slow getting the half-hourly data across. Dean notes that cancellations are replaced, and that the team answers every WhatsApp question quickly.
The model behind it is the same for every installer: TNW finds and qualifies the business, books the meeting into your diary and you pay per qualified, attended appointment, not per raw enquiry or a monthly retainer. Read how pay per appointment commercial solar leads work, or see the checks behind each booking in how to qualify commercial solar leads.
Results
- Loaded a couple of grand on a card and leads started coming through within 10 minutes.
- 5 surveys, 5 decision makers: finance director or MD at every single job, with a mix of 50kW, 100kW and larger sites.
- ~20 leads a day on WhatsApp, full detail, handpicked and earmarked exclusively to him.
- 4 out of 5 serious: only one prospect was slow on data; cancellations get replaced free.
Want results like Castle Eco Solutions?
TNW Marketing books pre-qualified, exclusive commercial solar site meetings for installers. TNW's show rate is 60%+, and you pay per qualified, attended appointment with no retainer and no minimum spend. See the commercial projects ready for survey now.
More client results
SRC North West case study3 to 4 strong opportunities in about two months, one with a letter of authority to approach the DNO.
Solar Solutions case studyEngaged, vetted commercial customers and more leads than he could keep up with.
Ingeni Renewables case studyWork won directly from TNW leads, including a straightforward ~36kW system with a purchase order in.
See all 28 commercial solar installer case studies, plus residential solar results.
Related guides for installers
- Pay per appointment commercial solar leads
How paying per attended site appointment works, how it compares with pay per lead and retainers, and what counts as an attended meeting.
- Solar leads UK: compare providers
Solar installer leads for sale in the UK: 12 providers compared on lead type, price, contract and no-show terms, and pay per appointment from £250.
- Lead Pronto alternatives for solar installers
What Lead Pronto offers, from its own website, and six alternative UK solar lead suppliers compared on lead type, exclusivity, price, contract and no-shows.
- Exclusive vs shared commercial solar leads
What each costs and why, who carries the no-show risk, how to check a supplier's exclusivity claim, and when shared leads can make sense.
- In-house vs outsourced lead generation: the real cost
What an in-house appointment setter really costs, line by line, against buying booked appointments, with a cost-per-meeting calculator.
- Pay per lead vs retainer vs pay per appointment
Cost, risk, contract terms and lead quality side by side, and when a retainer can still make sense.
- Choosing a solar marketing agency
Full-service agencies, lead suppliers and pay-per-booking lead generation compared, the channels that win commercial work, and what to ask before you sign.
- Renewable energy marketing agency (UK)
Renewable energy marketing services compared, inbound vs outbound, retainer vs pay per booking, and why commercial solar is the one thing TNW does.
- Appointment setting for solar installers
What appointment setting is, how agencies charge, in-house vs outsourced setters, UK rules on B2B calls and email, and what to ask before you sign.
- Commercial solar tenders and frameworks
Where UK solar PV tenders are published, which public sector frameworks have solar lots, what buyers ask for and how bids are scored.
- Commercial solar PPAs for installers
How a rooftop or private wire PPA works, the parties and contract terms, which customers qualify, what funders ask for, and the alternatives.
- Public sector solar funding: PSDS, Salix and GB Energy
What has closed (PSDS) and what is open now: Great British Energy solar for schools and the NHS, Salix loans in Scotland and Wales, and how installers win the work.
- Offering finance on commercial solar
Hire purchase, leasing and PPAs compared, and when the FCA rules on credit broking apply: individuals, the £25,000 business exemption and introducer ARs.
- Solar EPC contractors explained
Engineering, procurement and construction vs design and build, the FIDIC, NEC and JCT contract forms, typical EPC terms and subcontracting to an EPC.
- VAT, CIS and the reverse charge on commercial solar
The VAT rate on commercial jobs, when the construction reverse charge applies, invoice wording, and CIS registration, deductions and returns, from HMRC.
- Roof overcladding or replacement before solar
For roofers and solar installers: overclad or re-roof first, asbestos and structural checks, RC62 fire classification, the Part L upgrade, sequencing and tax.
- UK solar statistics: the commercial market in numbers
Official UK solar statistics: capacity and installations by size band and region, growth trends, 2030 targets and business energy prices, all with sources.
- UK commercial solar statistics (data tables)
Year-by-year DESNZ tables since 2010: capacity and installations by size band, the commercial bands month by month, generation and share of electricity, with a CSV.
- LinkedIn lead generation for commercial solar
Win commercial solar site surveys from LinkedIn: who to target, Sales Navigator vs free, example messages, LinkedIn's limits and the UK data rules.
- Cold email for commercial solar
Cold email for commercial solar: who to email, UK rules (PECR, UK GDPR), deliverability set-up, example emails and follow-ups, and what it really takes.
- Cold calling commercial solar
Book commercial solar site surveys by phone: call lists, TPS/CTPS screening, switchboard, opening, qualifying and objection scripts, and the UK rules.
- Commercial solar prospecting from public data
Build a target list before you call: Companies House SIC codes, the EPC and DEC registers, Land Registry ownership data and SECR energy reports.
- Commercial solar installer case studies
Video interviews with installers using TNW: site meetings booked, system sizes, deals closed and what changed for their business.
- Lead calculator
Work out how many site surveys and leads you need to hit your monthly installation target, from your own booking and close rates.
- Solar cost per lead calculator
What each signed job really costs you, profit after lead spend, and the most you can pay per lead or booked appointment, with a side-by-side comparison.
- How to generate commercial solar leads
The channels UK commercial installers use to book site surveys, what "qualified" really means and the numbers to track.
- How solar leads are priced
How solar leads are priced: per lead, per booked or attended appointment, retainer or revenue share, and shared vs exclusive.
- How much do solar leads cost? UK price list
Cost per lead vs cost per booked meeting, what drives the price, and how to work out what you can afford to pay.
- Solar lead follow-up: speed to lead and no-shows
Call new leads within minutes, a first-week follow-up plan, confirming the survey twice and the five reasons booked surveys don't happen.
- How to qualify commercial solar leads
A five-point checklist and the first-call questions that stop surveyors driving to sites that will never sign.
Browse every installer guide on the guides hub.
