The following has evaluated to null or missing:
==> .vars['reserved-article-group-id'] [in template "161555#161602#ARTICLE-PAGE---HERO" at line 14, column 20]
----
Tip: It's the final [] step that caused this error, not those before it.
----
Tip: If the failing expression is known to legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??
----
----
FTL stack trace ("~" means nesting-related):
- Failed at: #assign groupId = .vars["reserved-art... [in template "161555#161602#ARTICLE-PAGE---HERO" at line 14, column 1]
----
1<#assign namespace = randomNamespace />
2<#assign JSONFactoryUtil = staticUtil["com.liferay.portal.kernel.json.JSONFactoryUtil"] />
3<#assign journalArticleLocalService = serviceLocator.findService("com.liferay.journal.service.JournalArticleLocalService") />
4<#assign containerId = randomNamespace />
5<#assign shareURL = themeDisplay.getPortalURL()+themeDisplay.getURLCurrent()/>
6
7<#-- Auto-assign ALL category to every article -->
8<#assign assetCategoryLocalService = serviceLocator.findService("com.liferay.asset.kernel.service.AssetCategoryLocalService") />
9<#assign assetEntryLocalService = serviceLocator.findService("com.liferay.asset.kernel.service.AssetEntryLocalService") />
10<#assign journalArticleLocalService = serviceLocator.findService("com.liferay.journal.service.JournalArticleLocalService") />
11
12<#-- Get current JournalArticle -->
13<#assign articleId = .vars['reserved-article-id'].data />
14<#assign groupId = .vars['reserved-article-group-id'].data?number />
15<#assign journalArticle = journalArticleLocalService.getArticle(groupId, articleId) />
16
17<#-- Get AssetEntry for this article -->
18<#assign assetEntry = assetEntryLocalService.getEntry("com.liferay.journal.model.JournalArticle", journalArticle.getResourcePrimKey()) />
19
20<#-- Your ALL category ID -->
21<#assign allCategoryId = 4614994 />
22
23<#-- Assign ALL category if not already set -->
24<#if !assetEntry.getCategories()?seq_contains(assetCategoryLocalService.getCategory(allCategoryId))>
25 <#assign categoryIds = assetEntry.getCategoryIds() + [allCategoryId] />
26 ${assetEntryLocalService.updateEntry(
27 assetEntry.getUserId(),
28 assetEntry.getGroupId(),
29 assetEntry.getClassName(),
30 assetEntry.getClassPK(),
31 assetEntry.getUuid(),
32 assetEntry.getClassTypeId(),
33 categoryIds,
34 assetEntry.getTagNames()
35 )}
36</#if>
37
38<div class="hero jmarticle__hero-main-container">
39 <div class="container">
40 <div class="row">
41 <div class="article__cont">
42 <h1 class="article__heading">${Title.getData()}</h1>
43 <#if (SubTitle.getData())??>
44 <p class="article__para">
45 ${SubTitle.getData()}
46 </p>
47 </#if>
48
49 <#assign Date_Data=getterUtil.getString(Date.getData())>
50 <#if validator.isNotNull(Date_Data)>
51 <p class="article__date">
52 <#assign Date_DateObj=dateUtil.parseDate("yyyy-MM-dd", Date_Data, locale)>
53 ${dateUtil.getDate(Date_DateObj, "dd MMMM yyyy", locale)}
54 </p>
55 </#if>
56
57 <#if Link_Title?? && Link_Title.getData()?has_content>
58 <#list Link_Title.getSiblings() as cur_Link_Title>
59 <#if cur_Link_Title?? && cur_Link_Title.getData()?has_content>
60 <#assign linkHref="#" />
61 <#assign target="" />
62
63 <#assign rowId = containerId + cur_Link_Title?index />
64 <#if cur_Link_Title.Link_Internal?? && cur_Link_Title.Link_Internal.getFriendlyUrl()?has_content>
65 <#assign linkHref=cur_Link_Title.Link_Internal.getFriendlyUrl() />
66 <#elseif cur_Link_Title.Link_Media?? && cur_Link_Title.Link_Media.getData()?has_content>
67 <#assign linkHref=cur_Link_Title.Link_Media.getData() />
68 <#elseif cur_Link_Title.Link_Mailto?? && cur_Link_Title.Link_Mailto.getData()?has_content>
69 <#assign linkHref="mailto:" + cur_Link_Title.Link_Mailto.getData() />
70 <#elseif cur_Link_Title.Link_External?? && cur_Link_Title.Link_External.getData()?has_content>
71 <#assign linkHref=cur_Link_Title.Link_External.getData() />
72 </#if>
73 <#if (cur_Link_Title.Link_Target??) && (cur_Link_Title.Link_Target.getData())?has_content>
74 <#assign target=cur_Link_Title.Link_Target.getData() />
75 </#if>
76 <div id="blue_button_click_div" data-analytics-asset-type="custom">
77 <div class="jmarticle__hero-btn-list">
78 <a id="panel_blue_button_${rowId}" class="article__btn" href="${linkHref}" title="${cur_Link_Title.getData()}" target="${target}" data-analytics-asset-action="click" onclick="onBlueButtonClick(this)" >
79 <span class="btn__text">${cur_Link_Title.getData()}</span>
80 <span class="arrow__forward"></span>
81 </a>
82 </div>
83 </div>
84 </#if>
85 </#list>
86 </#if>
87 <div class="article-download-share">
88
89 <#if PDFTitle?? && PDFTitle.getData()?has_content>
90 <#assign title = PDFTitle.getData() />
91 <#assign pdf_link = "#" />
92 <#assign pdfrowId = containerId />
93 <#if PDFTitle.PDF?? && PDFTitle.PDF.getData()?has_content>
94 <#assign pdf_link = PDFTitle.PDF.getData() />
95 </#if>
96 <div class="article-download">
97 <div id="blue_button_click_div" data-analytics-asset-type="custom">
98 <div class="jmarticle__hero-btn-list">
99 <a id="panel_blue_button_${pdfrowId}" class="article__btn" href="${pdf_link}" title="${title}" data-analytics-asset-action="click" onclick="onBlueButtonClick(this)">
100 <span class="btn__text">${title}</span>
101 <span class="arrow__forward"></span>
102 </a>
103 <a id="panel_blue_button_${pdfrowId}" class="article__btn-mobile" href="${pdf_link}" title="${title}" data-analytics-asset-action="click" onclick="onBlueButtonClick(this)">
104 <img src="${themeDisplay.getPathThemeImages()}/new__jm__images/download-white-icon.svg" alt="twitter image"/>
105 </a>
106 </div>
107 </div>
108 </div>
109 </#if>
110
111 </div>
112
113 </div>
114 </div>
115 <#if (ImageLarge.getData())?? && ImageLarge.getData() != "">
116 <div class="row jmarticle__hero-banner" id="jmarticle__hero-${namespace}"
117 style="background-image: url(${ImageLarge.getData()})">
118 </#if>
119
120 </div>
121 </div>
122</div>
123
124<#if Author?? && Author.getData()?has_content>
125 <div class="jmarticle__author-info">
126 <div class="container">
127 <div class="hero__bar">
128 <#list Author.getSiblings() as cur_Author>
129 <#if cur_Author?? && cur_Author.getData()?has_content>
130 <#assign
131 webContentData = jsonFactoryUtil.createJSONObject(cur_Author.getData())
132 gId = groupId
133 journalArticle = journalArticleLocalService.getArticleByUrlTitle(gId, webContentData.title)
134 docXML = saxReaderUtil.read(journalArticle.getContent())
135
136 fName = docXML.valueOf("//dynamic-element[@name='FullName']/dynamic-content/text()")
137 jobTitle = docXML.valueOf("//dynamic-element[@name='JobTitle']/dynamic-content/text()")
138 role = docXML.valueOf("//dynamic-element[@name='ContactInfo']/dynamic-content/text()")
139 photoXML = docXML.valueOf("//dynamic-element[@name='Photo']/dynamic-content/text()")
140 photoSrc = JSONFactoryUtil.createJSONObject(photoXML).getString("uuid")
141 fullName = docXML.valueOf("//dynamic-element[@name='Title']/dynamic-content/text()")
142 authorImageXML = docXML.valueOf("//dynamic-element[@name='ImageLarge']/dynamic-content/text()")
143 authImageSrc = JSONFactoryUtil.createJSONObject(authorImageXML).getString("uuid")
144 summary = docXML.valueOf("//dynamic-element[@name='Summary']/dynamic-content/text()")
145 />
146
147 <div class="author">
148 <figure class="author__image">
149 <#if authImageSrc?? && authImageSrc?has_content>
150 <img src="/documents/${groupId}/${authImageSrc}" alt="${fullName}" class="author_img_class_new">
151 <#elseif photoSrc?? && photoSrc?has_content>
152 <img src="/documents/${groupId}/${photoSrc}" alt="${fName}" class="author_img_class_new">
153 </#if>
154 </figure>
155 <div class="author__details d-flex flex-column">
156 <h3 class="author__name">
157 <a rel="author">
158 <#if fullName?? && fullName?has_content>
159 ${fullName}
160 <#elseif fName?? && fName?has_content>
161 ${fName}
162 </#if>
163 </a>
164 </h3>
165 <p class="author__desc text-size-a author_job_title">
166 <#if jobTitle?? && jobTitle?has_content>
167 ${jobTitle}
168 </#if>
169 </p>
170 <span>
171 <p class="author__desc text-size-a">
172 <#if summary?? && summary?has_content>
173 ${summary}
174 </#if>
175 <#if role?? && role?has_content>
176 ${role}
177 </#if>
178 </p>
179 </span>
180 </div>
181 <div>
182 <div class="author__contact">
183 <ul class="author__contact-list">
184 </ul>
185 </div>
186 </div>
187 </div>
188 </#if>
189 </#list>
190 </div>
191 </div>
192 </div>
193</#if>
194
195
196
197<div class="container">
198 <div class="row">
199 <div class="article__intro">
200 <#if (Introduction.getData())??>
201 ${Introduction.getData()}
202 </#if>
203
204 <div class="article-download-share">
205
206 <#if PDFTitle?? && PDFTitle.getData()?has_content>
207 <#assign title = PDFTitle.getData() />
208 <#assign pdf_link = "#" />
209 <#assign pdfrowId = containerId />
210 <#if PDFTitle.PDF?? && PDFTitle.PDF.getData()?has_content>
211 <#assign pdf_link = PDFTitle.PDF.getData() />
212 </#if>
213 <div class="article-download">
214 <div id="blue_button_click_div" data-analytics-asset-type="custom">
215 <div class="jmarticle__hero-btn-list">
216 <a id="panel_blue_button_${pdfrowId}" class="article__btn" href="${pdf_link}" title="${title}" data-analytics-asset-action="click" onclick="onBlueButtonClick(this)">
217 <span class="btn__text">${title}</span>
218 <span class="arrow__forward"></span>
219 </a>
220 <a id="panel_blue_button_${pdfrowId}" class="article__btn-mobile" href="${pdf_link}" title="${title}" data-analytics-asset-action="click" onclick="onBlueButtonClick(this)">
221 <img src="${themeDisplay.getPathThemeImages()}/new__jm__images/download-white-icon.svg" alt="twitter image"/>
222 </a>
223 </div>
224 </div>
225 </div>
226 </#if>
227
228
229 <div class="article-share">
230 <a href="https://linkedin.com/shareArticle?url=${shareURL}&title=<#if (Title.getData())??>${Title.getData()}</#if>" target="_blank">
231 <img class="socialicons__img" src="${themeDisplay.getPathThemeImages()}/new__jm__images/social_icons-LinkedIN.png" alt="twitter image"/>
232 </a>
233 <a href="https://twitter.com/share?url=${shareURL}&text=<#if (Title.getData())??>${Title.getData()}</#if>" target="_blank">
234 <img class="socialicons__img" src="${themeDisplay.getPathThemeImages()}/new__jm__images/social_icons-Twitter.png" alt="twitter image"/>
235 </a>
236 </div>
237 </div>
238
239 </div>
240 </div>
241</div>
242
243<style>
244 img.author_img_class_new {
245 width: 100% !important;
246 height: 100% !important;
247 position: absolute;
248 margin: auto;
249 top: 0;
250 bottom: 0;
251 }
252
253 .article__btn:focus-visible {
254 outline: 2px solid blue !important;
255}
256
257@media (min-width: 320px) and (max-width: 650px) {
258 .article__intro li {
259 margin-left: -32px !important;
260 }
261 .journal-content-article .container .article__intro {
262 margin-top: 22px !important;
263}
264}
265@media (min-width: 540px) and (max-width: 834px) {
266 .article__intro li {
267 margin-left: -32px !important;
268 }
269 .article__intro {
270 margin: 60px 15px 0 5px !important;
271 }
272}
273
274@media (min-width: 320px) and (max-width: 539px){
275.jmarticle__author-info {
276 padding: 0px 0;
277}
278.jmarticle__author-info .author__image {
279 width: 39px;
280 height: 40px;
281}
282
283.jmarticle__author-info .author__name a {
284 line-height: 0px;
285 font-size: 18px !important;
286 margin-right: 10px;
287}
288
289.jmarticle__author-info .author__desc {
290
291 line-height: 14px;
292 font-size: 12px !important;
293 margin-bottom: 7px;
294}
295}
296
297</style>
If technology advances – in transport, manufacturing and everyday electrical appliances – represent one of modern society’s greatest triumphs, then one of its greatest challenges lies in delivering those same conveniences and capabilities without increasing global temperatures. Cars, planes and trains have transformed the way we travel, just as automation has revolutionised factory environments. Moving backwards is not an option. In the modern, mobile and digitised world – in which high-energy technologies are often the bellwethers for a country’s economic strength – we must seek alternative routes to energy.
In May, the Committee on Climate Change (CCC) published its Net Zero report, exploring “The UK’s contribution to stopping global warming”. The move to Net Zero provides a great opportunity for UK plc, with its tremendous heritage of world-leading innovation – particularly to find solutions for the hard to decarbonise areas such as heavy goods vehicles, locomotives and space heating.
What has been made very clear by both the Intergovernmental Panel on Climate Change (IPCC) and CCC is that our current plans for climate change mitigation are not enough. A Net Zero target requires systemic changes to the entire energy landscape. It is also clear that there won’t be one single solution; we need a toolkit of technologies to address the wide range of energy uses that are supported by government policy and changes to how we live our lives. These technologies exist; however there is no market or policy drivers in place for their widespread deployment.
Despite its simplicity – a hydrogen atom comprises just one proton and one electron – hydrogen only exists in trace amounts on Earth. It can be produced in different ways, but today most hydrogen is manufactured by steam methane reforming, where, at high temperatures using processes and catalysts developed by Johnson Matthey and others, natural gas is converted to hydrogen and CO2. In the future hydrogen will probably also be produced at similar scale by splitting water into its components of oxygen and hydrogen through electrolysis. In both cases the process can be decarbonised by using renewable energy for electrolysis or capturing the CO2 from advanced reforming technologies and storing it in a process called carbon capture and storage (CCS). That hydrogen can then be used to produce heat and power or used in vehicles with a drastically reduced emissions footprint.
While there has been focus on fuel cell vehicles recently, it is the sectors more difficult to decarbonise that could benefit the most from hydrogen. How do we decarbonise domestic heating, provide flexible dispatchable power generation and decarbonise high-temperature processes in industry?
As the availability of low-cost, low-carbon hydrogen grows it will find more application in other sectors with a lowering of associated cost from production at scale. A key recommendation from the CCC report and others over the last year is that we cluster low-carbon hydrogen production in areas of high-CO2 emissions so that we can cost-effectively implement CCS, also essential for a low-carbon society.
A country’s mobility capability, in general, is a critical economic factor. As well as determining individual convenience, it represents how goods and services are moved around. A school or hospital cannot serve communities effectively without good mobility to match. Hydrogen can help to provide safe, clean, reliable and noiseless travel that is comfortable and efficient for its users. And according to a report from the Environmental Audit Committee, air pollution costs the NHS over £50bn each year. Delivering cleaner energy is a public health concern as well as a central factor in achieving resource efficiency.
The interest in hydrogen as an alternative fuel is largely driven by the potential to manufacture hydrogen at scale with low-carbon emissions. Cars powered by hydrogen fuel cells have additional advantages over other alternative, zero-emission (at point of use) vehicles, such as those powered by batteries. They can be refuelled in a few minutes (faster than electric vehicles can be currently recharged) and have ranges typical of current gasoline and diesel-powered cars.
Where other fuel processes produce energy through combustion, fuel cells produce it electrochemically. Fuel cells, like traditional batteries, consist of an anode, a cathode and an electrolyte membrane. A typical fuel cell moves hydrogen to the anode, where it is split into its constituent proton and electron. The proton then travels through a membrane electrolyte to the cathode, where it reacts with oxygen (from the air), generating water, while the electrons complete a circuit and, in the case of a fuel cell vehicle, drive the electric motors. As there is no combustion aspect to fuel cell power generation and there are no moving parts, they operate almost silently as well as very efficiently.
Fuel cells are, effectively, batteries that won’t run flat or have their capacity reduced with each charge. Provided there is fuel (hydrogen) in the tank (stored on board the vehicle), the process can continue. As fuel cells can be stacked into a “series”, the more fuel cells you combine, the more power you can generate at any one time.
While hydrogen and fuel cells’ case is strong in the long term, the main challenge in upscale is in delivering the infrastructure to support this technology. A hydrogen economy can only be realised with the right level of government support through proactive policy and investment. If we are to expect more people to start using hydrogen fuel cell cars, then more hydrogen refuelling stations must be built and positioned strategically.
Collaboration between government, industry and academia is vital to making hydrogen generation as efficient as possible in the first place, and in installing the infrastructure to enable hydrogen use at scale. The UK has a great record of innovation, and the move towards a hydrogen economy offers great opportunities for UK plc to implement existing technologies based on hydrogen, and to develop new, more efficient ones, which other countries will need as they also look to decarbonise their economies.
Relative to some of the world’s larger economies, the UK’s impact on the global climate through its energy use is small. But supporting the hydrogen economy and leading by example can set a standard for other countries to follow. If the UK gets its own hydrogen economy right, there’s every chance that others will too. With the right commitment to learning by doing, collaboration and investment, it could emerge as a world leader in this vital source of alternative energy.
Authors
Sam French: New Markets Manager, Johnson Matthey
Andy Walker: Technical Marketing Director, Johnson Matthey
Article originally published in the NewStatesman on 17th May 2019.
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