Achieving Very High PV Penetration

This article argues that optimally deployed intermittency solutions could affordably transform solar power generation into the firm power delivery system modern economies require, thereby enabling very high solar penetration and the displacement conventional power generation. The optimal deployment of these high‐penetration enabling solutions imply the existence of a healthy power grid, and therefore imply a central role for utilities and grid operators. This article also argues that a value‐based electricity compensation mechanism, recognizing the multifaceted, penetration‐dependent value and cost of solar energy, and capable of shaping consumption patterns to optimally match resource and demand, would be an effective vehicle to enable high solar penetration and deliver affordable firm power generation

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

A Palaeocene intracanyon-style lava emplaced during the early shield-building stage of the Cuillin Volcano, Isle of Skye, NW Scotland

The twin summits of Preshal More and Preshal Beg, near Talisker, Isle of Skye, comprise the erosional remnants of a thick (at least 120 m) compound olivine tholeiite lava, or flow field, that ponded in palaeo-valleys within the Palaeocene lava field of west-central Skye. This unique flow field constitutes the Talisker Formation and is the youngest preserved extrusive unit of the Skye Lava Field. The lava inundated a complex of palaeo-valleys incised into the higher stratigraphical levels of the existing lava field, and remnants of the original sedimentary fill of these valleys still exist, the Preshal Beg Conglomerate Formation. The lava displays spectacularly well-developed two-tier (colonnade-entablature) columnar joint sets that formed as a consequence of slow, uninterrupted cooling through its base and sidewalls, aided by groundwater circulation and water ingress (from displaced drainage) directed into the lava's interior by master-joint systems. Intrusive phenomena developed at both the base and the top of the lava and there is evidence for the existence of subsurface feeder tubes. The tholeiitic composition of the Talisker Formation lava contrasts with the transitional, mildly alkaline characteristics of the remainder of the (older) lavas of Skye Lava Field. In broad terms, the Talisker Formation lava is compositionally very similar to the suite of cone-sheets emplaced into the oldest of the four intrusive centres that comprise the Skye Central Complex – the Cuillin Intrusive Centre – together with a high proportion of the Skye regional dyke swarm. The stratigraphical position, field relationships and compositional characteristics of the lava indicate that it was erupted and emplaced as an intracanyon-style flow field during the early shield-building stage in the growth of the (tholeiitic) Cuillin Volcano, which post-dates the main Skye ‘plateau’ Lava Field. Although the remnant outcrops are detached from their likely source area through erosion, this tholeiitic lava provides the first direct evidence linking the central complexes of the British Palaeogene Igneous Province and their eruptive products