diff --git a/src/schema/pathwayTimeseries.v2.json b/src/schema/pathwayTimeseries.v2.json
index ca7224f1..16072f6e 100644
--- a/src/schema/pathwayTimeseries.v2.json
+++ b/src/schema/pathwayTimeseries.v2.json
@@ -132,6 +132,8 @@
               "nuclear",
               "biomass",
               "hydro",
+              "geothermal",
+              "energyStorage",
               "renewables",
               "electricVehicles",
               "hydrogenVehicles",
@@ -298,6 +300,7 @@
         "then": {
           "properties": {
             "technology": {
+              "$comment": "Exactly the Power technology keys of src/utils/timeseriesTaxonomy.ts, which the plots and the CSV download look every row up in; pathwayTimeseries.v2.test.ts checks the two agree. Every value must also be in the all-sector enum above, because both lists apply to a Power row: `geothermal`, `battery` and `hydrogen` used to be listed here only, so they could never validate (#977). Storage is `energyStorage` (cookbook decision 0020), matching the `Energy storage` segment.",
               "type": ["string", "null"],
               "enum": [
                 "coal",
@@ -309,9 +312,8 @@
                 "solar",
                 "biomass",
                 "geothermal",
-                "hydrogen",
+                "energyStorage",
                 "renewables",
-                "battery",
                 "other",
                 null
               ]
diff --git a/src/schema/pathwayTimeseries.v2.test.ts b/src/schema/pathwayTimeseries.v2.test.ts
index db2a667f..9eb8eebb 100644
--- a/src/schema/pathwayTimeseries.v2.test.ts
+++ b/src/schema/pathwayTimeseries.v2.test.ts
@@ -2,8 +2,56 @@ import { describe, it, expect } from "vitest";
 import timeseriesJson from "./pathwayTimeseries.v2.json" with { type: "json" };
 import { commonSchemas } from "./common/index.ts";
 import { validateFilesBySchema } from "../utils/validateData";
+import { SECTORS_BY_KEY } from "../utils/timeseriesTaxonomy";
 import ieaSteps from "../data/iea/IEA-STEPS-2024_timeseries.json" with { type: "json" };
 
+/** The slice of the schema these assertions read. */
+interface RowSchema {
+  properties: { technology: { enum: (string | null)[] } };
+  then: { properties: { technology: { enum: (string | null)[] } } };
+}
+
+const row = (
+  timeseriesJson as unknown as {
+    properties: { data: { items: RowSchema } };
+  }
+).properties.data.items;
+const allSectors = row.properties.technology.enum;
+const power = row.then.properties.technology.enum;
+
+describe("pathwayTimeseries.v2 Power technologies (#977)", () => {
+  it("are exactly the taxonomy's Power technology keys", () => {
+    // The plots and the CSV download look every row's technology up in the
+    // taxonomy, so the schema must not allow one it cannot resolve.
+    const taxonomy = Object.keys(SECTORS_BY_KEY.power.technologies ?? {});
+    expect(power.filter((t) => t !== null).sort()).toEqual(taxonomy.sort());
+    expect(power).toContain(null); // a sector-level row has no technology
+  });
+
+  it("are all in the all-sector enum too, since both lists apply", () => {
+    expect(power.filter((t) => !allSectors.includes(t))).toEqual([]);
+  });
+
+  const validate = (technology: string) => {
+    const doc = structuredClone(ieaSteps) as {
+      data: { technology: unknown }[];
+    };
+    doc.data = [{ ...doc.data[0], technology }];
+    return validateFilesBySchema(
+      [{ name: "row.json", data: doc }],
+      [timeseriesJson, ...commonSchemas],
+    );
+  };
+
+  it.each(["geothermal", "energyStorage"])("accepts a %s row", (technology) => {
+    expect(validate(technology).invalid).toEqual([]);
+  });
+
+  it.each(["battery", "hydrogen"])("rejects the retired %s", (technology) => {
+    expect(validate(technology).invalid).toHaveLength(1);
+  });
+});
+
 /** A real file with one field replaced, validated against the v2 schema. */
 const validateWith = (over: Record<string, unknown>) =>
   validateFilesBySchema(
diff --git a/src/types/pathwayTimeseries.v2.d.ts b/src/types/pathwayTimeseries.v2.d.ts
index 725e004b..52a14c72 100644
--- a/src/types/pathwayTimeseries.v2.d.ts
+++ b/src/types/pathwayTimeseries.v2.d.ts
@@ -117,6 +117,8 @@ export interface PathwayTimeseriesV2 {
       | "nuclear"
       | "biomass"
       | "hydro"
+      | "geothermal"
+      | "energyStorage"
       | "renewables"
       | "electricVehicles"
       | "hydrogenVehicles"