Physicist. Unlocking ambitious solutions to societal challenges Managing Director Deeptech and Ecosystem at Techleap. Co-founder at RIFF Lecturer. Author. TED Speaker.https://bsky.app/profile/gregdt.bsky.socialhttps://bsky.app/profile/gregdt.bsky.social/post/3ms4apyn45c24So long London!!! Today is my last day as a Londoner and from tonight on I will be an Amsterdamer… Mixed feelings as I love London but excited by what is coming02 Aug 2026 14:59 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3ms4apyn45c24https://bsky.app/profile/gregdt.bsky.social/post/3mrk4aa3pps2tHow the cost of useful energy has evolved for fossil fuels and modern “clean” technologies Spot the difference (Talking about costs not prices) https://www.sciencedirect.com/science/article/pii/S254243512200410X26 Jul 2026 09:51 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mrk4aa3pps2thttps://bsky.app/profile/gregdt.bsky.social/post/3mrhepxn73c2mLess clouds, less glaciers. The earth is absorbing more sunlight and warming faster. And this is caused by climate change itself which is caused by the 1800 billion tons of CO2 we have emitted…25 Jul 2026 07:45 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mrhepxn73c2mhttps://bsky.app/profile/gregdt.bsky.social/post/3mqz6z4p3x22nGreat data viz by @ourworldindata.org showing the largest source of electricity in countries across the globe. Clearly a coal cluster in Southeast Asia and a lot of gas countries Nuclear dominates in a few countries only19 Jul 2026 16:25 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mqz6z4p3x22nhttps://bsky.app/profile/gregdt.bsky.social/post/3mqefpaqwjc2vEurope is too slow on electrification and it is a big problem. Despite 2 major energy crises, the narrative remains vague. The countries (like China) who are pulling ahead will maintain an advantage for quite some time. Nice wake up call from Fatih Birol in @financialtimes.com11 Jul 2026 09:59 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mqefpaqwjc2vhttps://bsky.app/profile/gregdt.bsky.social/post/3mq2w67rlm22jLi-ion batteries costs decrease every time the installed capacity doubled. A recent studies looked at battery costs since 1991 (first Li-ion battery) and found that EVs became the driver for cost declines from 2000 (Toyota Prius). The learning rate since 2000 has been 25%07 Jul 2026 15:27 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mq2w67rlm22jhttps://bsky.app/profile/gregdt.bsky.social/post/3mpyhtdiais2xElectricity is probably the most versatile form of energy. It can produce force, heat, light, computation, chemicals In addition, the range of electrical power we use spans about 20 orders of magnitude from very low power electronics to the 22.5GW of 3 gorge dam (log scale below)06 Jul 2026 16:05 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mpyhtdiais2xhttps://bsky.app/profile/gregdt.bsky.social/post/3mptlwcdwn22oReminder that an energy system based on combustion is very inefficient. Going from primary energy to useful energy, one loses almost 2/3 - a pity given that we extract close to 17 billion tons of fossil fuels per year. Electrification is a massive opportunity for efficiency!04 Jul 2026 17:35 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mptlwcdwn22ohttps://bsky.app/profile/gregdt.bsky.social/post/3mozn6cgf222sElectricity is poised to become the workhorse of the energy system. For massive electrification to happen, that electricity needs to be abundant AND cheap. High time for policy-makers to work on electricity prices, the EU industry desperately needs that... https://www.ft.com/content/f2415750-c42f-490b-83e1-41172f00e70a?syn-25a6b1a6=124 Jun 2026 09:48 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mozn6cgf222shttps://bsky.app/profile/gregdt.bsky.social/post/3mnorbyhtic2kIn 2025, global coal capacity increased by 3.5% but generation of electricity from coal decreased by 0.6%. This trend is particularly notable in China and India where renewables met the load growth. Coal plants are built as insurance more than primary resource07 Jun 2026 08:38 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mnorbyhtic2khttps://bsky.app/profile/gregdt.bsky.social/post/3mnn2wb3jgs2qGreat illustration of how carbon dioxide removal and emission reductions are complementary to reach the point where climate change will stop. And the less reduction we do, the less interesting/relevant removal is since removal is always more expensive.06 Jun 2026 16:25 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mnn2wb3jgs2qhttps://bsky.app/profile/gregdt.bsky.social/post/3mnmaeec5ss2wCool graph from @bloomberg.com showing the evolution of data centre capacity and the planned/announced projects. Data centres globally now consume close to 500TWh- basically as much as Germany. https://www.bloomberg.com/graphics/2026-ai-data-center-redesign/?ai=eyJpc1N1YnNjcmliZWQiOnRydWUsImFydGljbGVSZWFkIjpmYWxzZSwiYXJ0aWNsZUNvdW50IjowLCJ3YWxsSGVpZ2h0IjoxfQ==06 Jun 2026 08:29 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mnmaeec5ss2whttps://bsky.app/profile/gregdt.bsky.social/post/3mnkr2ag54c2nProgress in batteries mean that they can now help decarbonise maritime transport. A recent paper shows that by 2030, electrification could apply to 30% of shipping energy demand and 20% GHG emissions… https://www.nature.com/articles/s44406-026-00026-8.pdf05 Jun 2026 18:23 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mnkr2ag54c2nhttps://bsky.app/profile/gregdt.bsky.social/post/3mn7kka4pb22nGreat read on what AI can do for science. Yes it has the potential to accelerate science but not it will not replace scientists. The paper also makes a great point about the need to maintain critical thinking and not blindly trust results https://www.amacad.org/publication/daedalus/unlocking-scientific-intuition-reasoning-at-digital-speed01 Jun 2026 07:27 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mn7kka4pb22nhttps://bsky.app/profile/gregdt.bsky.social/post/3mn5ktnph7s2dHydrogen versus batteries in road transport Hydrogen is far behind in every category one can think of, and the progress in batteries are only extending the gap. Perhaps time to totally stop talking about hydrogen for road transport? Source: https://www.iea.org/reports/global-ev-outlook-202631 May 2026 12:27 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mn5ktnph7s2dhttps://bsky.app/profile/gregdt.bsky.social/post/3mcryzwggys252025 is now officially the third hottest year in record history. Climate is changing fast and impacts being felt more and more. At this pace, the 1.5 degrees mark will be crossed before 2030 (remember it is a 20-yr average) Source: https://climate.copernicus.eu/global-climate-highlights-2025#:~:text=In%202025%2C%20annual%20surface%20air,clear%20long%2Dterm%20warming%20trend19 Jan 2026 15:57 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mcryzwggys25https://bsky.app/profile/gregdt.bsky.social/post/3mcpq2ammnk24Chinese EVs are cheaper than US EVs BUT also better. The graph below compares the price of both as a function of range. But Chinese cars also offer superior characteristics for example in terms of fast charge Great read here: https://www.science.org/doi/10.1126/science.adz054118 Jan 2026 18:11 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mcpq2ammnk24https://bsky.app/profile/gregdt.bsky.social/post/3mbhr37ffak26New Year, new challenges Happy to share that I'll be working on a new initiative this year to accelerate the emergence of radical ideas to solve big societal challenges and create a pipeline of investable and impactful scientific ventures. We call it RIFF...02 Jan 2026 20:43 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mbhr37ffak26https://bsky.app/profile/gregdt.bsky.social/post/3mb7gg5iszc2dThis is what the US department of Energy was posting on X (Twitter) before Christmas. Coal is the worst fossil fuel. There is no such thing as clean coal30 Dec 2025 13:11 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mb7gg5iszc2dhttps://bsky.app/profile/gregdt.bsky.social/post/3mb4nahlbck2gInteresting graph comparing investments in clean and fossil energy since 2015. https://techcrunch.com/2025/06/06/clean-energy-investment-hits-new-highs-and-shows-no-sign-of-slowing/29 Dec 2025 10:35 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3mb4nahlbck2ghttps://bsky.app/profile/gregdt.bsky.social/post/3m62r6uxi322qIt's now official With the 55 other intrepid runners that made the run we entered the @GWR Guinness World Records for the deepest marathon !!! What an adventure it was.20 Nov 2025 12:25 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3m62r6uxi322qhttps://bsky.app/profile/gregdt.bsky.social/post/3m5veju76js2iThe G-word and why we need to talk about it. In my latest Substack, I lay out some thoughts on Solar Radiation Modification (aka geo-engineering) and why we need more public research on the topic. Please subscribe (and react) https://riffonsolutions.substack.com/p/we-need-to-talk-about-the-g-word18 Nov 2025 08:55 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3m5veju76js2ihttps://bsky.app/profile/gregdt.bsky.social/post/3m5r7ezylv22eA great graph to explain what the energy transition - electricity is about 20% of final energy demand, we need to electrify most sectors (estimates now show that up to 70% is possible) - electricity is still 60% fossile so we need to decarbonise it https://ember-energy.org/latest-insights/the-electrotech-revolution/16 Nov 2025 17:12 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3m5r7ezylv22ehttps://bsky.app/profile/gregdt.bsky.social/post/3m4o4gzvbw22zThere are different ways to measure the global economy - 112 trillion dollars - 600 exajoules of primary energy, 400 in final energy - 107 billion tons of natural resources https://www.materialflows.net/visualisation-centre/data-visualisations/02 Nov 2025 18:16 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3m4o4gzvbw22zhttps://bsky.app/profile/gregdt.bsky.social/post/3m46xsevff22vWhen it comes to climate, doomism is a western luxury because we’re less affected. The future is what we make of it… the longer we wait to act the more severe the consequences of climate change will be27 Oct 2025 17:43 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3m46xsevff22vhttps://bsky.app/profile/gregdt.bsky.social/post/3m43ety7nv22cNot every day you break a word record. But for me this was yesterday!! We ran the world’s deepest marathon. An impressive immersion in a working mine26 Oct 2025 07:26 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3m43ety7nv22chttps://bsky.app/profile/gregdt.bsky.social/post/3m36ilpbw622zLaunching my Substack today !! This will build on the content I am sharing regularly on LinkedIn and provide deeper thoughts on the fast changing space of climate and deep tech. riffonsolutions.substack.com https://riffonsolutions.substack.com/14 Oct 2025 19:46 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3m36ilpbw622zhttps://bsky.app/profile/gregdt.bsky.social/post/3m2w5fj4ld2242 weeks to go before the World’s deepest marathon- 1.4 km below the surface. This is going to be a world record if we make it and this is also for charity. Any donation is appreciated worldsdeepestmarathon.raiselysite.com/greg-de-temmer…11 Oct 2025 12:04 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3m2w5fj4ld224https://bsky.app/profile/gregdt.bsky.social/post/3lu5qeq5ag22a100 days to go !!!! 🏃‍♂️ With a group of 60 people, we'll attempt a record-breaking marathon, 1,120m below sea level in Boliden's Garpenberg mine in Sweden. This is done to raise money for 2 charities and change discussions around mining (critical for energy...) Consider donating17 Jul 2025 10:36 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3lu5qeq5ag22ahttps://bsky.app/profile/gregdt.bsky.social/post/3lts6rhttj22kMy family is against electric cars… Have been listening to all the usual misinformation arguments for 90 minutes and people wonder why I am quiet…12 Jul 2025 20:22 +0000at://did:plc:bdhx5rofmoqde5hhpaa2dwza/app.bsky.feed.post/3lts6rhttj22k